- Visual observation: (10x lens) Look for color, luster, cut, doublet/triplet junctions, if any.
- Determine optic character: Single refractive (SR) / Double refractive (DR) / Anomalous Double refractive (ADR) / Aggregate (AGG).
- Spectrum: Many stones may have diagnostic spectrum.
- Microscope: Inclusions may be diagnostic, but look for inclusions that differentiate natural and synthetic, doublet / triplet.
- Fluorescence: Look under shortwave and longwave for diagnostic colors.
- Immersion cell: Use immersion cell and high refractive index liquid to separate doublets/triplets.
- Refractometer: Confirm spectroscope reading with refractometer.
The fancy colored stones, which may resemble one another in appearance and values, are:
Diamond
- Hardness: 10
- Specific gravity: 3.52
- Refractive index: 2.42
- Optic sign: SR/ADR
- Birefringence: -
- Other points: negative refractive index, dispersion, luster, look at the girdle plane; cleavage, inclusions, weak to strong fluorescence in long wave (may be inert). Diamonds may be treated. Sapphire, synthetic sapphire, spinel, synthetic spinel, zircon, synthetic rutile, synthetic yttrium aluminum garnet (YAG), synthetic gadolium gallium garnet (GGG), synthetic strontium titanate, synthetic cubic zircona (CZ), topaz, quartz, demantoid garnet, sphene, and glass may look like diamond. Standard / analytical techniques may be required to detect treatments / identify the stones.
Synthetic cubic zirconia
- Hardness: 8.5
- Specific gravity: 5.60 – 6.0
- Refractive index: 2.15 – 2.18 (average)
- Optic sign: SR
- Birefringence: -
- Other points: color, negative refractive index, dispersion, luster, orange flash on the pavilion, girdle, inclusions, fluorescence. Gem quality stones are relatively clean. Standard / analytical techniques may be required to identify the stones.
Synthetic strontium titanate
- Hardness: 5.5
- Specific gravity: 5.13
- Refractive index: 2.41
- Optic sign: SR
- Birefringence: -
- Other points: color, negative refractive index, dispersion, luster, girdle, inclusions, fluorescence, rounded facet edges. Gem quality stones are relatively clean. Standard / analytical techniques may be required to identify the stones.
Synthetic gadolium gallium garnet (GGG)
- Hardness: 6.5
- Specific gravity: 7.05
- Refractive index: 1.97
- Optic sign: SR
- Birefringence: -
- Other points: color, negative refractive index, dispersion, luster, girdle, color, inclusions, fluorescence (strong orange yellow (LW) and yellow (SW)), rounded facet edges. Gem quality stones are relatively clean. Standard / analytical techniques may be required to identify the stones.
Synthetic yttrium aluminum garnet (YAG)
- Hardness: 8.5
- Specific gravity: 4.58
- Refractive index: 1.83
- Optic sign: SR
- Birefringence: -
- Other points: color, negative refractive index, dispersion, luster, girdle, inclusions, fluorescence (variable). Gem quality stones are relatively clean. Standard / analytical techniques may be required to identify the stones.
Synthetic rutile
- Hardness: 6.5
- Specific gravity: 4.25
- Refractive index: 2.61 – 2.90
- Optic sign: Uniaxial positive
- Birefringence: DR; 0.287
- Other points: color, negative refractive index, strong dispersion, luster, doubling of back facets, inclusions, rounded facet edges. Gem quality stones are relatively clean. Standard / analytical techniques may be required to identify the stones.
Demantoid garnet
- Hardness: 6.5
- Specific gravity: 3.85
- Refractive index: 1.89
- Optic sign: SR
- Birefringence: -
- Other points: color, negative refractive index reading, dispersion. Gem quality stones are relatively clean. Standard / analytical techniques may be required to identify the stones.
Zircon
- Hardness: 7.5
- Specific gravity: 4.69
- Refractive index: 1.93 -1.99
- Optic sign: Uniaxial positive
- Birefringence: DR; 0.059
- Other points: color, dispersion, negative refractive index, luster, inclusions, doubling of back facets, spectrum. Gem quality stones are relatively clean. Standard / analytical techniques may be required to identify the stones.
Sphene
- Hardness: 5.5
- Specific gravity: 3.53
- Refractive index: 1.89 – 2.02
- Optic sign: Biaxial positive
- Birefringence: DR; 0.13
- Other points: color, dispersion, negative refractive index, luster, inclusions, doubling of back facets, spectrum. Gem quality stones are relatively clean. Standard / analytical techniques may be required to identify the stones.
Benitoite
- Hardness: 6.5
- Specific gravity: 3.67
- Refractive index: 1.76 – 1.80
- Optic sign: Uniaxial positive
- Birefringence: DR; 0.047
- Other points: Color, inclusions, fluorescence, spectrum, dispersion. Standard / analytical techniques may be required to identify the stones.
Friday, January 19, 2007
Diamond-studded future for Botswana
(via National Jeweler Network) iAfrica writes:
Botswana, the world's largest diamond producer, is targeting a 17-fold increase in its fledgling cutting industry within five years.
It also aims to provide its diamond mines with all support services from local sources, President Festus Mogae said on Tuesday. He announced that the local cutters would be part supplied direct from a producer, as well as the De Beers' Diamond Trading Company, which until now has been the exclusive marketing channel for Botswana production.
Diamond centre
"We can and will graduate from a diamond producing country to a world class diamond centre," Mogae told delegates from the international industry at a dinner in Antwerp, Belgium.
"The cutting and polishing industry in Botswana has been very small, cutting diamonds worth about $30-million per annum. It is our wish the 16 companies now licensed to operate in Botswana should in five years' time be cutting and polishing at least half a billion dollars worth of diamonds per annum," he said.
Botswana was aiming to develop its diamond industry, not only to polish and cut stones across the market, but also to provide all other financial and technical support services. This would be helped by the migration to Botswana by 2008 of industry services carried out by the De Beers' Diamond Trading Company (DTC) in London, primarily the aggregation of rough production.
"This will attract related services to Botswana, such as diamond banking, security, insurance, security, technology and engineering as well as grading or diamond laboratories," Mogae said.
Better balance
He has previously stated that a major reason for development of cutting and polishing was to help alleviate Botswana's growing unemployment; but in Antwerp stressed this must not happen by the industry concentrating on lesser skilled operations to satisfy the larger volumes sold at the lower end of the market.
"We hope that there will be a balance between employment creation through the cutting of smaller goods and profitable operation which means cutting higher value goods. It is indeed our hope that all companies will do everything possible to ensure employment creation but we also recognise that they should be viable," he said.
The DTC's Botswana operation (DTCB) would become operational in 2008 and be a joint partnership between De Beers and the Botswana government, as is its present diamond producer Debswana.
"All diamond manufacturers in Botswana will become clients of DTCB," Mogae said. "It will supply them with mixtures rather than Debswana-only production, at DTC determined prices which we trust will be market related."
Allay fears
Whilst Debswana markets exclusively through the DTC, the local cutters would also be supplied direct by Diamonex, an Australian- and Botswana-listed company whose projects are entirely in Botswana. Its Martin's Drift property, due to commence production during 2007, comprises kimberlites previously discovered by De Beers.
"The diamonds from this producer will be made available to companies in Botswana outside of the DTC system, also at market prices. They will only be exported if the cutting and polishing companies in Botswana do not buy them," Mogae said.
This is not seen as the beginning of a move towards direct marketing of all Botswana production but rather as a possible way to allay fears that bringing rough diamonds onto the market in Botswana might open up a channel for the introduction of conflict diamonds.
De Beers and Botswana were architects of the Kimberley Process, which seeks to prevent trade in the small number of gems produced to fund conflict in Africa. Last year, De Beers Botswana chief executive, Sheila Khama, registered concern about opening the sealed and secure process to sell to local cutters.
"Nothing we do to develop the cutting and polishing industry will be allowed to interfere with the Kimberley Process," she said.
More info @ http://business.iafrica.com/news/590862.htm
Botswana, the world's largest diamond producer, is targeting a 17-fold increase in its fledgling cutting industry within five years.
It also aims to provide its diamond mines with all support services from local sources, President Festus Mogae said on Tuesday. He announced that the local cutters would be part supplied direct from a producer, as well as the De Beers' Diamond Trading Company, which until now has been the exclusive marketing channel for Botswana production.
Diamond centre
"We can and will graduate from a diamond producing country to a world class diamond centre," Mogae told delegates from the international industry at a dinner in Antwerp, Belgium.
"The cutting and polishing industry in Botswana has been very small, cutting diamonds worth about $30-million per annum. It is our wish the 16 companies now licensed to operate in Botswana should in five years' time be cutting and polishing at least half a billion dollars worth of diamonds per annum," he said.
Botswana was aiming to develop its diamond industry, not only to polish and cut stones across the market, but also to provide all other financial and technical support services. This would be helped by the migration to Botswana by 2008 of industry services carried out by the De Beers' Diamond Trading Company (DTC) in London, primarily the aggregation of rough production.
"This will attract related services to Botswana, such as diamond banking, security, insurance, security, technology and engineering as well as grading or diamond laboratories," Mogae said.
Better balance
He has previously stated that a major reason for development of cutting and polishing was to help alleviate Botswana's growing unemployment; but in Antwerp stressed this must not happen by the industry concentrating on lesser skilled operations to satisfy the larger volumes sold at the lower end of the market.
"We hope that there will be a balance between employment creation through the cutting of smaller goods and profitable operation which means cutting higher value goods. It is indeed our hope that all companies will do everything possible to ensure employment creation but we also recognise that they should be viable," he said.
The DTC's Botswana operation (DTCB) would become operational in 2008 and be a joint partnership between De Beers and the Botswana government, as is its present diamond producer Debswana.
"All diamond manufacturers in Botswana will become clients of DTCB," Mogae said. "It will supply them with mixtures rather than Debswana-only production, at DTC determined prices which we trust will be market related."
Allay fears
Whilst Debswana markets exclusively through the DTC, the local cutters would also be supplied direct by Diamonex, an Australian- and Botswana-listed company whose projects are entirely in Botswana. Its Martin's Drift property, due to commence production during 2007, comprises kimberlites previously discovered by De Beers.
"The diamonds from this producer will be made available to companies in Botswana outside of the DTC system, also at market prices. They will only be exported if the cutting and polishing companies in Botswana do not buy them," Mogae said.
This is not seen as the beginning of a move towards direct marketing of all Botswana production but rather as a possible way to allay fears that bringing rough diamonds onto the market in Botswana might open up a channel for the introduction of conflict diamonds.
De Beers and Botswana were architects of the Kimberley Process, which seeks to prevent trade in the small number of gems produced to fund conflict in Africa. Last year, De Beers Botswana chief executive, Sheila Khama, registered concern about opening the sealed and secure process to sell to local cutters.
"Nothing we do to develop the cutting and polishing industry will be allowed to interfere with the Kimberley Process," she said.
More info @ http://business.iafrica.com/news/590862.htm
The Diamond World
By David E Koskoff
Published by Harper & Row Publishers, New York
ISBN 0-06-038005-5
1981
Harper & Row Publishers writes:
When Randolph Churchill, father of Winston, peered down into the vastness of “The Big Hole of Kimberley”, the great worked out diamond mine, and contemplated what it represented in human terms, he mused. “All for the vanity of woman.” To which one of the women in the party added, “And the depravity of man.” The Diamond World is about the vanity of women and the depravity of men.
On one level, of course, the book is about diamonds: it traces the stone from mine to finger. On another level, though, this book is about very different matters: smuggling in Zaire (DR Congo), corruption in Sierre Leone, income tax evasion in Israel, child labor in India, murder in New York and perversion of Japanese values. An incisive economic dissection of the world’s most glittering business, this book is also an anthropological, sociological, and political look at the world’s shabbiest business—the diamond trade.
The Diamond World is about the ways in which De Beers Consolidated Mines Limited, the giant South African corporation that controls diamond distribution, has attained and maintained control of the diamond world, and the benevolent and malevolent faces of its power. It is about the diamantaires; the people involved in one or more aspects of the diamond industry and trade, and about the honor code that governs them, and which makes them quite possibly the world’s most honest businessmen—within their own group. Their honor code, however, has never had much relevance to the outside world; they victimize both consumers and the countries that shelter them, particularly the United States, Israel, and Belgium.
The diamond world is so secretive that even its New York labor union has an unlisted telephone number. “It’s like a prison system,” one customs official told the author. “If you talk,’ others won’t deal with you, buy from you or sell to you.” Nonetheless, with gall and charm—and mostly perseverance—David Koskoff worked his way into the arcane and colorful circle of the diamond people and managed to interview hundreds of them: small ‘diamond diggers’ prospecting for diamonds with more hope than knowledge; De Beers and other diamond mining executives on three continents; twelve-year old diamond polishers in the diamond cottages of India; jewelers in high priced goods and in schlock. Mostly people were evasive; with few exceptions; they do have something to hide. But from fragments of each person’s comments, Koskoff was able to piece together the puzzle of the diamond world. In the process he traveled around the world—to Amsterdam and Antwerp, Tel Aviv, India, Hong Kong, Tokyo; to South Africa, Namibia, Botswana, Zaire, Ghana, Liberia and Sierre Leone.
There have been other books about the diamond world, but none that has so totally bared the inner machinations of the world’s most mysterious business.
About The Author
David E Koskoff, a practicing attorney, is the author of Joseph P Kennedy; A Life and Times and The Mellons: The Chronicle of America’s Richest Family. He lives in Plainville, Connecticut, with his wife, Charlotte.
David E Koskoff writes:
“Get the coat! Get the coat!” Harry Samuelson’s father yelled from the ship’s railing to his son on the wharf. “Go back to the hotel, pay the bill, and get the coat!”
Harry suspected what was afoot. The ship, from Virgo, Spain, to Cuba, was fully booked; the Samuelsons had appreciated that they would have to wait for the next boat to freedom. They had done to the docks only to say goodbye to some luckier friends, other Jewish refugees from Hitler, who had obtained the last berths available. Once aboard, though, the friends warned Harry’s father: Spain might change its tolerant policy toward the Jews; there might not be a next boat. This might be the Samuelson’s last chance to escape. The friends were willing to help. At length Harry’s father made the determination: They would stow away. Standing on the wharf, Harry, fifteen years old, pieced that much together.
But why the coat? What of their luggage, their important belongings? Why had his father neglected to mention these things of value? In Cuba it would be warm; his father would not even need an overcoat.
Harry rushed back to the hotel, threw the family’s most valuable possessions into a suitcase, and with a mine-is-not-to-reason-why sigh, put the useless overcoat on his own back and returned to the dock. With a surreptitiously obtained pass, he boarded ship, and when it embarked for Cuba and freedom, the Samuelsons—seven in all—were aboard, secreted in their friend’s cabin.
When the ship was well at sea, the Samuelsons confided in a Catholic priest, who brought young Harry to see the ship’s purser to make the family’s explanations and try to smooth things over. The purser was outraged to learn that there were stowaways on his ship and was not to be mollified by a mere boy. He demanded to see Harry’s father immediately.
Harry was terrified. Would they order that the ship be turned around, and hand the family over to the authorities as common criminals? Or worse, deport them to Spain across the border to Vichy France, where the Nazis were in firm control? He returned to the family’s hiding place where his father calmly heard what had occurred.
No, the father would not go to see the purser. Instead, he said, Harry must return to see the purser—this time alone, without the priest. He was to tell the purser that they were honest people, that they would pay for the passage, that they were grateful for his understanding and for his assistance, and—fumbling about in the lining of his old overcoat—that they wanted the purser to have a token of their appreciation. The father removed his hand from within the coat and dropped something into Harry’s palm: one shiny pebble.
Today Harry Samuelson is an important diamond dealer in Antwerp, Belgium, the capital of the world diamond trade. He has forgotten much in a full life, but he will always remember the look on the purser’s face when Harry gave him the diamond. “You can’t imagine how his face lit up; I saw a smile like I’ve never seen in my whole life.” And he remembers the wonderful trip to Cuba—everything was first class al the way. He remembers, too, the coat, the old overcoat, and what was sewn into his lining, the family’s passport to freedom.
Published by Harper & Row Publishers, New York
ISBN 0-06-038005-5
1981
Harper & Row Publishers writes:
When Randolph Churchill, father of Winston, peered down into the vastness of “The Big Hole of Kimberley”, the great worked out diamond mine, and contemplated what it represented in human terms, he mused. “All for the vanity of woman.” To which one of the women in the party added, “And the depravity of man.” The Diamond World is about the vanity of women and the depravity of men.
On one level, of course, the book is about diamonds: it traces the stone from mine to finger. On another level, though, this book is about very different matters: smuggling in Zaire (DR Congo), corruption in Sierre Leone, income tax evasion in Israel, child labor in India, murder in New York and perversion of Japanese values. An incisive economic dissection of the world’s most glittering business, this book is also an anthropological, sociological, and political look at the world’s shabbiest business—the diamond trade.
The Diamond World is about the ways in which De Beers Consolidated Mines Limited, the giant South African corporation that controls diamond distribution, has attained and maintained control of the diamond world, and the benevolent and malevolent faces of its power. It is about the diamantaires; the people involved in one or more aspects of the diamond industry and trade, and about the honor code that governs them, and which makes them quite possibly the world’s most honest businessmen—within their own group. Their honor code, however, has never had much relevance to the outside world; they victimize both consumers and the countries that shelter them, particularly the United States, Israel, and Belgium.
The diamond world is so secretive that even its New York labor union has an unlisted telephone number. “It’s like a prison system,” one customs official told the author. “If you talk,’ others won’t deal with you, buy from you or sell to you.” Nonetheless, with gall and charm—and mostly perseverance—David Koskoff worked his way into the arcane and colorful circle of the diamond people and managed to interview hundreds of them: small ‘diamond diggers’ prospecting for diamonds with more hope than knowledge; De Beers and other diamond mining executives on three continents; twelve-year old diamond polishers in the diamond cottages of India; jewelers in high priced goods and in schlock. Mostly people were evasive; with few exceptions; they do have something to hide. But from fragments of each person’s comments, Koskoff was able to piece together the puzzle of the diamond world. In the process he traveled around the world—to Amsterdam and Antwerp, Tel Aviv, India, Hong Kong, Tokyo; to South Africa, Namibia, Botswana, Zaire, Ghana, Liberia and Sierre Leone.
There have been other books about the diamond world, but none that has so totally bared the inner machinations of the world’s most mysterious business.
About The Author
David E Koskoff, a practicing attorney, is the author of Joseph P Kennedy; A Life and Times and The Mellons: The Chronicle of America’s Richest Family. He lives in Plainville, Connecticut, with his wife, Charlotte.
David E Koskoff writes:
“Get the coat! Get the coat!” Harry Samuelson’s father yelled from the ship’s railing to his son on the wharf. “Go back to the hotel, pay the bill, and get the coat!”
Harry suspected what was afoot. The ship, from Virgo, Spain, to Cuba, was fully booked; the Samuelsons had appreciated that they would have to wait for the next boat to freedom. They had done to the docks only to say goodbye to some luckier friends, other Jewish refugees from Hitler, who had obtained the last berths available. Once aboard, though, the friends warned Harry’s father: Spain might change its tolerant policy toward the Jews; there might not be a next boat. This might be the Samuelson’s last chance to escape. The friends were willing to help. At length Harry’s father made the determination: They would stow away. Standing on the wharf, Harry, fifteen years old, pieced that much together.
But why the coat? What of their luggage, their important belongings? Why had his father neglected to mention these things of value? In Cuba it would be warm; his father would not even need an overcoat.
Harry rushed back to the hotel, threw the family’s most valuable possessions into a suitcase, and with a mine-is-not-to-reason-why sigh, put the useless overcoat on his own back and returned to the dock. With a surreptitiously obtained pass, he boarded ship, and when it embarked for Cuba and freedom, the Samuelsons—seven in all—were aboard, secreted in their friend’s cabin.
When the ship was well at sea, the Samuelsons confided in a Catholic priest, who brought young Harry to see the ship’s purser to make the family’s explanations and try to smooth things over. The purser was outraged to learn that there were stowaways on his ship and was not to be mollified by a mere boy. He demanded to see Harry’s father immediately.
Harry was terrified. Would they order that the ship be turned around, and hand the family over to the authorities as common criminals? Or worse, deport them to Spain across the border to Vichy France, where the Nazis were in firm control? He returned to the family’s hiding place where his father calmly heard what had occurred.
No, the father would not go to see the purser. Instead, he said, Harry must return to see the purser—this time alone, without the priest. He was to tell the purser that they were honest people, that they would pay for the passage, that they were grateful for his understanding and for his assistance, and—fumbling about in the lining of his old overcoat—that they wanted the purser to have a token of their appreciation. The father removed his hand from within the coat and dropped something into Harry’s palm: one shiny pebble.
Today Harry Samuelson is an important diamond dealer in Antwerp, Belgium, the capital of the world diamond trade. He has forgotten much in a full life, but he will always remember the look on the purser’s face when Harry gave him the diamond. “You can’t imagine how his face lit up; I saw a smile like I’ve never seen in my whole life.” And he remembers the wonderful trip to Cuba—everything was first class al the way. He remembers, too, the coat, the old overcoat, and what was sewn into his lining, the family’s passport to freedom.
Thursday, January 18, 2007
How To Separate Frequently Encountered Green Stones
- Visual observation: (10x lens) Look for color, luster, cut, doublet/triplet junctions, if any.
- Determine optic character: Single refractive (SR) / Double refractive (DR) / Anomalous Double refractive (ADR) / Aggregate (AGG).
- Spectrum: Many green stones may have diagnostic spectrum.
- Microscope: Inclusions may be diagnostic, but look for inclusions that differentiate natural and synthetic, doublet / triplet.
- Dichroscope: Different cutting orientations of natural and synthetic corundum / beryl may be revealed by dichroscope.
- Fluorescence: Look under shortwave and longwave for diagnostic colors.
- Immersion cell: Use immersion cell and high refractive index liquid to separate doublets/triplets.
- Refractometer: Confirm spectroscope reading with refractometer.
The green stones, which may resemble one another in appearance and values, are:
Fluorite
- Hardness: 4
- Specific gravity: 3.18
- Refractive index: 1.434
- Optic sign: SR
- Birefringence: -
- Other points: Inclusions, color, Chelsea color filter. Fluorite may be treated. Gem quality fluorites are relatively clean. Common look-alikes include emerald, tsavorite garent, peridot, demantoid garnet, green sapphire and glass. Standard / analytical techniques may be required to detect treatments / identify the stones.
Chalcedony (stained)
- Hardness: 6.5
- Specific gravity: 2.60
- Refractive index: 1.53 (mean)
- Optic sign: AGG (aggregate)
- Birefringence: -
- Other points: Color, stain, Chelsea color filter, inclusions. Chalcedony may be treated. Common look-alikes include jadeite jade, nephrite jade and glass. Standard identification techniques may be required to detect treatments.
Emerald
- Hardness: 7.5
- Specific gravity: 2.70 (average)
- Refractive index: 1.57 – 1.58
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.006
- Other points: Color, inclusions, spectrum, fluorescence. To separate natural vs synthetic use microscope. Most emeralds are treated. Clean emeralds are difficult to find. Common look-alikes include fluorite, tsavorite garnet, demantoid garnet, peridot and glass. Standard / analytical techniques may be required to detect treatments / identify the stones.
Synthetic emerald
- Hardness: 7.5
- Specific gravity: 2.70 (average)
- Refractive index: 1.57 – 1.58
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.003
- Other points: Color, inclusions, fluorescence, spectrum. Flux and hydrothermal stones may show diagnostic inclusions. Most gem quality stones are relatively clean. Standard / analytical techniques may be required to identify the stones if they are clean.
Tourmaline
- Hardness: 7
- Specific gravity: 3.05
- Refractive index: 1.62 – 1.64
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.018
- Other points: Color, pleochroism, inclusions. Most tourmalines are treated. Gem quality stones are relatively clean. Common look-alikes include peridot, tsavorite garnet, chrome diopside, green sapphire, emerald and glass. Standard / analytical techniques may be required to detect treatments / identify the stones.
Jadeite jade
- Hardness: 7
- Specific gravity: 3.34
- Refractive index: 1.66 (mean)
- Optic sign: AGG (aggregate)
- Birefringence: -
- Other points: Color, inclusions, spectrum, Chelsea color filter. Most jadeite jades are treated. Common look-alikes include nephrite jade, chalcedony, serpentine, green zoisite, soapstone, idocrase, aventurine quartz and glass. Standard / analytical techniques may be required to detect treatments.
Peridot
- Hardness: 6.5
- Specific gravity: 3.34
- Refractive index: 1.65 – 1.69
- Optic sign: Biaxial positive
- Birefringence: DR; 0.037
- Other points: Color, inclusions, spectrum, birefringence, doubling of back facets. Common look-alikes include tourmaline, chrome diopside, tsavorite garnet, demantoid garnet, green sapphire and glass. Standard identification techniques may be required to identify the stones.
Enstatite
- Hardness: 5.5
- Specific gravity: 3.20 – 3.00
- Refractive index: 1.65 – 1.68
- Optic sign: Biaxial positive
- Birefringence: DR; 0.010
- Other points: Color, inclusions, spectrum. Enstatite may look like peridot. Standard identification techniques may be required to identify the stones.
Diopside
- Hardness: 5
- Specific gravity: 3.30
- Refractive index: 1.67 – 1.70
- Optic sign: Biaxial positive
- Birefringence: DR; 0.025
- Other points: Color, inclusions, doubling of back facets. Common look-alikes include tourmaline, tsavorite garnet, demantoid garnet, peridot, green sapphire and glass. Gem quality stones are relatively clean. Standard identification techniques may be required to identify the stones.
Green zoisite
- Hardness: 6.5
- Specific gravity: 3.35
- Refractive index: 1.69 – 1.70
- Optic sign: Biaxial positive
- Birefringence: DR; 0.009
- Other points: Color, pleochroism, inclusions. Green zoisite may be treated. Gem quality stones are relatively clean and may look like alexandrite. Translucent to opaque quality stones may look like jadeite jade, aventurine quartz or glass. Standard / analytical techniques may be required to detect treatments / identify the stones.
Tsavorite garnet
- Hardness: 7.25
- Specific gravity: 3.65
- Refractive index: 1.75
- Optic sign: SR
- Birefringence: -
- Other points: Color, inclusions. Common look-alikes include chrome diopside, green tourmaline, green sapphire, demantoid garnet, peridot, emerald and glass. The stones may be treated. Gem quality stones are relatively clean. Standard / analytical techniques may be required to identify the stones.
Demantoid garnet
- Hardness: 6.5
- Specific gravity: 3.85
- Refractive index: 1.89
- Optic sign: SR
- Birefringence: -
- Other points: Color, inclusions, spectrum, dispersion, negative refractive index. Common look-alikes include tsavorite garnet, green tourmaline, chrome diopside, green sapphire, peridot, emerald and glass. The stones may be treated. Standard / analytical techniques may be required to detect treatments / identify the stones.
Chrysoberyl
- Hardness: 8.5
- Specific gravity: 3.72
- Refractive index: 1.74 – 1.75
- Optic sign: Biaxial positive
- Birefringence: DR; 0.009
- Other points: Color, inclusions, spectrum. Common look-alikes include green sapphire, tsavorite garnet, demantoid garnet, peridot, tourmaline, fluorite and glass. The stones may be treated. Standard / analytical techniques may be required to detect treatments / identify the stones.
Green sapphire
- Hardness: 9
- Specific gravity: 4
- Refractive index: 1.76 – 1.77
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.008
- Other points: Color, inclusions, spectrum. Common look-alikes include tsavorite garnet, demantoid garnet, green zircon, peridot, chrome diopside, green tourmaline and glass. The stones may be treated. Standard / analytical techniques may be required to identify treatments / identify the stones.
Green zircon
- Hardness: 6.5
- Specific gravity: 4
- Refractive index: 1.82 (values are variable)
- Optic sign: Uniaxial positive
- Birefringence: DR; 0.01
- Other points: Color, inclusions, negative refractive index, doubling of back facets, spectrum. Common look-a likes include green sapphire, peridot, chrome diopside, peridot, chrysoberyl, tsavorite garnet, demantoid garnet, emerald and glass. The stones may be treated. Standard / analytical techniques may be required to detect treatments / identify the stones.
Synthetic cubic zirconia
- Hardness: 8.5
- Specific gravity: 5.65 +
- Refractive index: 2.15 +
- Optic sign: SR
- Birefringence: -
- Other points: Color, negative refractive index reading, luster, dispersion. Standard / analytical techniques may be required to identify the stones.
Diamond
- Hardness: 10
- Specific gravity: 3.52
- Refractive index: 2.42
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Rare; color, negative refractive index reading, luster, dispersion, spectrum, inclusions. Green diamonds may be treated. Analytical techniques may be required to detect treatments.
Syntheic green diamond
- Hardness: 10
- Specific gravity: 3.52
- Refractive index: 2.42
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Color, negative refractive index reading, luster, dispersion, spectrum, inclusions. Synthetic diamonds are produced by high pressure high temperature method. Gem quality stones are relatively clean. Analytical techniques may be required to identify the stones.
Glass
- Hardness: 5.5
- Specific gravity: 3.70
- Refractive index: 1.60 – 1.66
- Optic sign: SR
- Birefringence: -
- Other points: Color, soft, inclusions (gas bubbles, swirls), luster. Standard identification techniques may be required to identify the stones.
Assembled Stones
Doublets / Triplets
Beryl composites
Refractive index: 1.57 -1.59
Birefringence: DR; 0.004
Other points: Immersion (Look for differences in color and luster between the sections)
Quartz soude (quartz/quartz)
- Refractive index: 1.54 -1.59
- Optic sign: Uniaxial positive
- Birefringence: DR; 0.009
- Other points: Look for differences in color and luster between the sections, gas bubbles)
Synthetic spinel soude (spinel / spinel)
- Refractive index: 1.728
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Look for differences in color and luster between the sections, gas bubbles)
Garnet topped doublet (glass)
- Refractive index: 1.76 +
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Look for differences in color and luster between the sections, gas bubbles)
- Determine optic character: Single refractive (SR) / Double refractive (DR) / Anomalous Double refractive (ADR) / Aggregate (AGG).
- Spectrum: Many green stones may have diagnostic spectrum.
- Microscope: Inclusions may be diagnostic, but look for inclusions that differentiate natural and synthetic, doublet / triplet.
- Dichroscope: Different cutting orientations of natural and synthetic corundum / beryl may be revealed by dichroscope.
- Fluorescence: Look under shortwave and longwave for diagnostic colors.
- Immersion cell: Use immersion cell and high refractive index liquid to separate doublets/triplets.
- Refractometer: Confirm spectroscope reading with refractometer.
The green stones, which may resemble one another in appearance and values, are:
Fluorite
- Hardness: 4
- Specific gravity: 3.18
- Refractive index: 1.434
- Optic sign: SR
- Birefringence: -
- Other points: Inclusions, color, Chelsea color filter. Fluorite may be treated. Gem quality fluorites are relatively clean. Common look-alikes include emerald, tsavorite garent, peridot, demantoid garnet, green sapphire and glass. Standard / analytical techniques may be required to detect treatments / identify the stones.
Chalcedony (stained)
- Hardness: 6.5
- Specific gravity: 2.60
- Refractive index: 1.53 (mean)
- Optic sign: AGG (aggregate)
- Birefringence: -
- Other points: Color, stain, Chelsea color filter, inclusions. Chalcedony may be treated. Common look-alikes include jadeite jade, nephrite jade and glass. Standard identification techniques may be required to detect treatments.
Emerald
- Hardness: 7.5
- Specific gravity: 2.70 (average)
- Refractive index: 1.57 – 1.58
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.006
- Other points: Color, inclusions, spectrum, fluorescence. To separate natural vs synthetic use microscope. Most emeralds are treated. Clean emeralds are difficult to find. Common look-alikes include fluorite, tsavorite garnet, demantoid garnet, peridot and glass. Standard / analytical techniques may be required to detect treatments / identify the stones.
Synthetic emerald
- Hardness: 7.5
- Specific gravity: 2.70 (average)
- Refractive index: 1.57 – 1.58
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.003
- Other points: Color, inclusions, fluorescence, spectrum. Flux and hydrothermal stones may show diagnostic inclusions. Most gem quality stones are relatively clean. Standard / analytical techniques may be required to identify the stones if they are clean.
Tourmaline
- Hardness: 7
- Specific gravity: 3.05
- Refractive index: 1.62 – 1.64
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.018
- Other points: Color, pleochroism, inclusions. Most tourmalines are treated. Gem quality stones are relatively clean. Common look-alikes include peridot, tsavorite garnet, chrome diopside, green sapphire, emerald and glass. Standard / analytical techniques may be required to detect treatments / identify the stones.
Jadeite jade
- Hardness: 7
- Specific gravity: 3.34
- Refractive index: 1.66 (mean)
- Optic sign: AGG (aggregate)
- Birefringence: -
- Other points: Color, inclusions, spectrum, Chelsea color filter. Most jadeite jades are treated. Common look-alikes include nephrite jade, chalcedony, serpentine, green zoisite, soapstone, idocrase, aventurine quartz and glass. Standard / analytical techniques may be required to detect treatments.
Peridot
- Hardness: 6.5
- Specific gravity: 3.34
- Refractive index: 1.65 – 1.69
- Optic sign: Biaxial positive
- Birefringence: DR; 0.037
- Other points: Color, inclusions, spectrum, birefringence, doubling of back facets. Common look-alikes include tourmaline, chrome diopside, tsavorite garnet, demantoid garnet, green sapphire and glass. Standard identification techniques may be required to identify the stones.
Enstatite
- Hardness: 5.5
- Specific gravity: 3.20 – 3.00
- Refractive index: 1.65 – 1.68
- Optic sign: Biaxial positive
- Birefringence: DR; 0.010
- Other points: Color, inclusions, spectrum. Enstatite may look like peridot. Standard identification techniques may be required to identify the stones.
Diopside
- Hardness: 5
- Specific gravity: 3.30
- Refractive index: 1.67 – 1.70
- Optic sign: Biaxial positive
- Birefringence: DR; 0.025
- Other points: Color, inclusions, doubling of back facets. Common look-alikes include tourmaline, tsavorite garnet, demantoid garnet, peridot, green sapphire and glass. Gem quality stones are relatively clean. Standard identification techniques may be required to identify the stones.
Green zoisite
- Hardness: 6.5
- Specific gravity: 3.35
- Refractive index: 1.69 – 1.70
- Optic sign: Biaxial positive
- Birefringence: DR; 0.009
- Other points: Color, pleochroism, inclusions. Green zoisite may be treated. Gem quality stones are relatively clean and may look like alexandrite. Translucent to opaque quality stones may look like jadeite jade, aventurine quartz or glass. Standard / analytical techniques may be required to detect treatments / identify the stones.
Tsavorite garnet
- Hardness: 7.25
- Specific gravity: 3.65
- Refractive index: 1.75
- Optic sign: SR
- Birefringence: -
- Other points: Color, inclusions. Common look-alikes include chrome diopside, green tourmaline, green sapphire, demantoid garnet, peridot, emerald and glass. The stones may be treated. Gem quality stones are relatively clean. Standard / analytical techniques may be required to identify the stones.
Demantoid garnet
- Hardness: 6.5
- Specific gravity: 3.85
- Refractive index: 1.89
- Optic sign: SR
- Birefringence: -
- Other points: Color, inclusions, spectrum, dispersion, negative refractive index. Common look-alikes include tsavorite garnet, green tourmaline, chrome diopside, green sapphire, peridot, emerald and glass. The stones may be treated. Standard / analytical techniques may be required to detect treatments / identify the stones.
Chrysoberyl
- Hardness: 8.5
- Specific gravity: 3.72
- Refractive index: 1.74 – 1.75
- Optic sign: Biaxial positive
- Birefringence: DR; 0.009
- Other points: Color, inclusions, spectrum. Common look-alikes include green sapphire, tsavorite garnet, demantoid garnet, peridot, tourmaline, fluorite and glass. The stones may be treated. Standard / analytical techniques may be required to detect treatments / identify the stones.
Green sapphire
- Hardness: 9
- Specific gravity: 4
- Refractive index: 1.76 – 1.77
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.008
- Other points: Color, inclusions, spectrum. Common look-alikes include tsavorite garnet, demantoid garnet, green zircon, peridot, chrome diopside, green tourmaline and glass. The stones may be treated. Standard / analytical techniques may be required to identify treatments / identify the stones.
Green zircon
- Hardness: 6.5
- Specific gravity: 4
- Refractive index: 1.82 (values are variable)
- Optic sign: Uniaxial positive
- Birefringence: DR; 0.01
- Other points: Color, inclusions, negative refractive index, doubling of back facets, spectrum. Common look-a likes include green sapphire, peridot, chrome diopside, peridot, chrysoberyl, tsavorite garnet, demantoid garnet, emerald and glass. The stones may be treated. Standard / analytical techniques may be required to detect treatments / identify the stones.
Synthetic cubic zirconia
- Hardness: 8.5
- Specific gravity: 5.65 +
- Refractive index: 2.15 +
- Optic sign: SR
- Birefringence: -
- Other points: Color, negative refractive index reading, luster, dispersion. Standard / analytical techniques may be required to identify the stones.
Diamond
- Hardness: 10
- Specific gravity: 3.52
- Refractive index: 2.42
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Rare; color, negative refractive index reading, luster, dispersion, spectrum, inclusions. Green diamonds may be treated. Analytical techniques may be required to detect treatments.
Syntheic green diamond
- Hardness: 10
- Specific gravity: 3.52
- Refractive index: 2.42
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Color, negative refractive index reading, luster, dispersion, spectrum, inclusions. Synthetic diamonds are produced by high pressure high temperature method. Gem quality stones are relatively clean. Analytical techniques may be required to identify the stones.
Glass
- Hardness: 5.5
- Specific gravity: 3.70
- Refractive index: 1.60 – 1.66
- Optic sign: SR
- Birefringence: -
- Other points: Color, soft, inclusions (gas bubbles, swirls), luster. Standard identification techniques may be required to identify the stones.
Assembled Stones
Doublets / Triplets
Beryl composites
Refractive index: 1.57 -1.59
Birefringence: DR; 0.004
Other points: Immersion (Look for differences in color and luster between the sections)
Quartz soude (quartz/quartz)
- Refractive index: 1.54 -1.59
- Optic sign: Uniaxial positive
- Birefringence: DR; 0.009
- Other points: Look for differences in color and luster between the sections, gas bubbles)
Synthetic spinel soude (spinel / spinel)
- Refractive index: 1.728
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Look for differences in color and luster between the sections, gas bubbles)
Garnet topped doublet (glass)
- Refractive index: 1.76 +
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Look for differences in color and luster between the sections, gas bubbles)
The Pearl Trader
By Louis Kornitzer
Published by Sheridan House, New York
1937
Sheridan House writes:
Lucky is the man whose life has been the pursuit of beauty and adventure. Louis Kornitzer, one of the great rare peal dealers of the world, is that man.
His autobiography, The Pearl Dealer, is one of the great autobiographies of our time—if not of all time—for it shows that a businessman may be an artist, an adventurer, a philosopher, and that one need not be an Axel Munthe, a Victor Heiser, or a Vincent Sheean to have lived a full, exciting, and intelligent life.
With the “world as his oyster” our author set out from London for the wide open, two gun pearl fishing town of Broome, Australia…from there to Sulu and Zamboanga (where the monkeys have no tails), when Black Jack Pershing was earning his gold stars chasing Moros into the hills----then to Hong Kong, where we get an inside view of the business ways for which the heathen Chinee is peculiar…from an odyssey through the Far East he sails back to London and Paris, where the great pearl traders nonchalantly toss about king’s ransoms in little tissue paper envelopes and where the author regales us with sophisticated tales of the vanity of men and the beauty of women.
A third division of this book is a short encyclopedia of pearl lore, which contains for the first time the intimate secrets of a pearl connoisseurs in their judgment of these subtle and moon-like gems.
Among the hundreds of good stories, anecdotes, and observations that tumble out of Kornitzer’s merry pages are those of the monkey who knew how many peanuts he could buy for a centavo…the Chinese clerk whose self-invented system of phonetics could record any sound from the spoken word to the flutter of a leaf…the dispute between the Canton vendor or roast cockroaches and the customer who purchased one of these dainties for a cash (about 1/20 of a cent) and then complained of its quality…the pearl dealer who was ruined by his honesty…Pigott, whose sense of humor saved his head…and the strange adventures of those wizards of skill, the pearl doctors.
Here you have an amusing record of a full life: wit, philosophy, anecdote, business experience, beauty, adventure, history, science and art.
The Pearl Trader is a human document of engrossing interest. There is not a single dull paragraph in its 384 pages.
About Louis Kornitzer
Author of The Pearl Trader
As a boy he sorted dirty seed pearls brought from the ghettos of Poland to his father’s shop…as a young man he learned the wiles of trading in the great gem marts of the world….as a man he traded with the wild Sea Dyaks of the Celebes, Mandarins with the culture of thousand of years a their finger tips, and Connemera Curraghmen who knew their values as well as the brokers of Maiden Lane.
He has left little or nothing out of his crowded life story, The Pearl Trader…you must read this book to savor fully one of the great personalities of our time.
The Pearl Merchants of Paris
Louis Kornitzer writes:
For a long time, a very long time, Paris has been the center of the pearl trade. The reason for this escapes me, unless it is that the many wealthy foreigners who visit it spend their money there more readily than they do anywhere else.
That, of course, would only be partial explanation, as would also the fact that the French gold and silversmiths are more than ordinarily skilled workers in precious metals. But as most of the important pearl fishing stations are situated in British possessions or adjoining them, and as nine-tenths of the pearls fished all over the world are consigned to London bankers and import houses, it is rather strange that Paris and not London should have become the great distributing center for this gem.
Within the last fifty years that part of the Rue Lafayette which runs from the Gare du Nord to within a few paces of the Grand Opera House has attracted numerous pearl merchants and brokers, whose offices are located in that thoroughfare. The Rue Lafayatte is to Pars what Hatton Garden is to London and Maiden Lane to New York—the headquarters of the trade in precious stones and pearls.
In any of these three thoroughfares there are to be seen throughout the whole year, irrespective of the season, and in practically all weathers short of tropical downpour or a hurricane, groups of men, for the most part sallow-complexioned, beak-nosed, and falcon-eyed, standing on the pavement or in the gutter, so that is sometimes difficult to pass. It is a hundred to one that these are more than fresh air fiends—that they are dealers or brokers in precious stones. Those who have a more refined appearance are undoubtedly the handlers of pearls. It would indeed be strange if the constant communion with the queen of gem had no refining influence.
If you are interested to discover which of them are dealers and which are brokers, you have only to peer into their faces. The haggard and pale, the worried-looking ones, those are the dealers. The sleekly-complacent and jesting ones are the brokers. Must I explain? The dealer has to take and give credit. Any error of judgment when appraising goods is upon his own head and his is the entire risk. But the broker is merely the go-between. Heads or tails, he wins. He obtains a brokerage from both buyer and seller, 1 per cent from either side, and the merchants have to pay him whether they register a gain or a loss.
You may wonder why, since the dealers know of each other’s existence, they do not trade directly and thus save the brokerage. They would certainly do so if they could, because brokerage is stiff tax, and no merchant is keen on curtailing his own profit or increasing his charges. But they cannot dispense with the broker. They have to tolerate him as the shark tolerates the pilot fish ( I trust the comparison will not be carried to extreme lengths).
The broker touts for business. He knows, or ought to know, the requirements of nearly everybody with whom he comes in contact. He is a kind of marriage broker. He is expected to praise the bride-to-be (vendor’s goods) and to extol the merits of the future bridegroom (the solvency of the buyer). He is a pimp of sorts, too, if you like. Yet it is to be acknowledged that he often acts the imperial judge and holds the scales of fairly even, and that more often than not he is worthy of his hire.
No, they are not all Jews, these Paris pearl- merchants and brokers. Many are Armenians, Syrians, Arabs, Parsees, Hindus, with a sprinkling of Neapolitans and Catalans and an odd Frenchman or two.
The appearance of many of them is not prepossessing. I grant you, and perhaps we would not be inclined to trust some of them out of our sight with a one cent stamp. Yet in some ways these men’s word is their bond. Their nod is as good as stamped agreement. Their verbal offer is binding. Parcels of pearls or other gems are handed from trader to trader and by them to brokers back and forth in an intricate chain, without acknowledgment in writing, without a receipt of any kind, and often without being checked over for contents. It is taken for granted by all concerned that the details of numbers and weights are correct and precisely as recorded on the wrappers containing the valuable merchandise.
Coming and going, there is implicit trust and almost child-like faith on this particular side of the business. Of chicanery there is plenty, as you will hear, but not in the important matter of ‘handing-round’ for sale, upon which the whole trade depends. Woe to the member of the closed circle, therefore, who betrays the confidence, reposed in him. His name is besmirched for evermore, and the gutter is his lot. The crook in the jewel trade is not honest because he loves virtue, but because he must be so.
The trade has peculiar customs, and by some of them the skinflint or the rogue has to abide, even when it hurts his pockets. There are, for example, times when a bargain, like a good steed, can be made to carry two.
Look at this particular group of four men standing on the curb of the Rue Lafayette. Each is acting according to his lights and his nature, and all are quite unselfconscious, for they do not know that thirty years later we shall be looking at them.
Of the four, the two well-groomed and prosperous-looking men are dealers; Senor Lopez, a Portuguese Jew, and Herr Ohnstadt, a naturalized Frenchman. Third is small shopkeeper from the Faubourg St.Germain. He is French from the tip of goatee to his prejudice against everything non-Gallic.
The fourth man does not know his own nationality. Neither Russians nor Poles will acknowledge him, but each try to wish him on to the other party. Meanwhile the French Government, which is patient with the alien sojourning in the midst, cannot send him over the frontier, because during forty years residence he has behaved himself properly. But he has never bothered about taking out naturalization papers to make himself Frenchman, and now he is a failure and may at any moment become a public charge, which is a crime in any country. Unhappy man! In this age of aggressive nationalism the life of an international no-account is not a happy one.
Ten short years ago he meant to retire and live on his rentes. Then he was prosperous. But he delayed too long, and the lean times came. When he could no longer afford to advise his business friends of his intended retirement—the postage being such a heavy item—he merely had to remain n harness. What else was there to do? And now he has no office; but the curb is a good place. Que voulez-vous? Offices are often stuffy, but here under God’s open sky one may breathe freely and catch one’s clients on the wing. By leave of the sergent de ville one may meet and foregather with old cronies, laugh at their stale jokes, until the voice of law and order says, ‘Pass along, Messieurs, pass along.’
Sometimes, though, not often, Nitchevitch’s bleary eyes are made to overflow with salty happiness when an old acquaintance nudges him en passant. Oh, it is good to be taken notice of when one gets old and—who says poor? No, no! We refuse to have that world applied to an old member of an exclusive circle who black coat shows not a single speck of dust and whose boots shine, veritably, like black pearls.
Sometimes, and generally after his wife has pointed to an empty larder, he may have to muster sufficient aggressiveness to squeeze himself into a deal. There is not always the opportunity, but it is going to present itself today even as we watch.
The French shopkeeper of the Rue du Bac in the Faubourg St.Germain is offering to Senor Lopez a fine secondhand jewel, a snuff box in solid gold exquisitely chased and set with Indian emeralds and rubies, and bordered with rose diamonds. Senor Lopez knows a genuine antique and scents a bargain. He really should not discuss the price at all, since it is being offered so cheaply, but pay what is asked; but from force of habit he fences for a rebate. However, at last, seeing that the deal is attracting the attention of the other dealers, he pulls out a roll of bedraggled notes and begins reluctantly to peel off the appropriate number.
But before the notes have had time to pass from buyer to seller, he who had contemplated retirement ten years ago on his own fat, and has now nothing but a couple of francs in his pocket, sings out, “Monsieur Lopez, I am in this deal with you up to a ten per cent risk!”
The Portuguese Jew looks daggers. But he can do nothing. Custom is rigid on the point. He knows well that there is no way of shaking off the infliction of an associate who is not going to invest a centime, who cannot contribute his share if a loss were to eventuate, and who will presently state how much he must be paid to be got rid of.
By and by, before the sun has gone down, Senor Lopez will offer Monsieur Nitchevitch so many hundred of francs to surrender his mythical interest. The latter, you might think, will be satisfied with any kind of offer, but not he. He will drive a desperate bargain, thinking all the time of the nagging wife at home and her empty larder. Finally, however, he will surrender his claim with a generous sweep of the hand, clutch nervously at the billes de cents, and make off to his obscure and mysterious abode.
You would perhaps call this blackmail. Business, strictly speaking, it is not. But it is the custom. On the whole, however, dealing in gems is a matter of diamond cut diamond and devil take the loser. Take the romantic tale of Jules Grun, Blisky, and Madame Moulin, depicting love among the pearl dealers.
It is really fortunate for you that I happen to know Jules Grun, the millionaire pearl merchant. Thus I take you to his office in that building on the other side of the street. Up one flight of stairs only, so we need not bother, about that narrow-chested wheezy lift. Here we are. Fine waiting room, luxurious carpets, handsome furniture, and the coziest of armchairs to make callers forget the painful suspense of waiting. But we will not sit down. Taking advantage of our cloak of darkness, we got right into the inner office and look about us.
Of the three people at work here you need take not notice at all of two. They are mere paid servants, nobodies. The one person who matters here, for he proclaims it often enough, is Jules Grun himself. There he sits, behind the large flat desk, bald-headed, full-faced, ruddy, and prosperous.
Besides ourselves there is another visitor, a visible one. He is an ordinary-looking person, Blisky by name, a broker. Everybody in the trade knows Blisky. Between Grun, the merchant, and Blisky, the broker, there lie on the table three bunches of oriental pearls. They have already given rise to great deal of talk before we came on the scence, but Blisky is still talking in the manner of brokers the world over, glibly and with serpentine guile, and there is nothing to show that he will ever stop.
Grun talks little. He contents himself with taking up one bunch after another, scrutinizing it carefully through a powerful lens, for the tenth time perhaps. Then he shakes his head from side to side, as pearl merchants do who are interested but intend to conceal it. Finally, he pushes them all together and towards the broker and grunts, “My first bid, Blisky, was more than generous. They are not worth more. You are foolish not to pass my offer on to your client.”
“I am very sorry, Monsieur Grun,” says Blisky, “but I have too much respect for myself to face my client with such a poor offer. He is temporarily embarrassed, as I told you, but there are limits.”
“People who are temporarily embarrassed for ready money should not deal in pearls,” says Grun pompously.
“Maybe yes and maybe no,” says Blisky in a huffed tone, “but as it is not my business to tell my clients what to do and what not to do, that gets us nowhere. You are acting crazy when you allow these bunches to slip through your fingers like this. I suppose you are so rich already that you absolutely refuse to make more money! You are getting to be such a hard nut, too, Monsieur, I warn you, that most brokers are scared to come to you. Were it not that four hundred thousand francs are not everyone’s money, I should not sit here now, be sure. But where in Paris is there another dealer who can lay his hands on so much cash at a moment’s notice?”
“But that is the reason, my dear Blisky, why I want to buy at my own price!”
Just then a clerk enters the room and hands the merchant a slip of paper. He glances at it and says, “Show the lady in,” and turning to the broker adds, “If you care to wait in the next room, I may have another look presently.”
There enters briskly, brushing past the retiring Blisky, a woman middle-aged, good-looking and self-possessed. With business-like directness she states her requirements immediately. A client of hers needs so many pearls of such a size and quality for three sautoirs. If Monsieur has them in stock, she can vouch for a sure sale and spot cash.
Grun almost gasps, but not quite. Strange coincidence! The fellow in the next room has the very thing tucked away in his leather wallet. What luck that he asked him to wait!
“Madame Moulin!,” he says impressively, “I believe I can accommodate your client, but the goods are out at the moment. If you will give me an hour, I will recall them and you can submit them to your client.”
Blisky, however, though a decent fellow and no eavesdropper, has happened to hear all this. The door has been left ajar by accident, and now he knows what is afoot. He decides he is tired of waiting, in spite of the luxuriousness of the waiting room and the comfort of the easy chair. He let himself out and travels down in the groaning lift—for he never believes in walking if he can ride.
He has not long to wait in the street below. Voiture! Voiture! There they go, Madame Moulin and Blisky, as fast as the crock in the shafts of the creaking four wheeler will take them, towards the glittering facades of the Rue de la Paix. The jeweler with whom they are presently closeted is in the worst position a jeweler can possibly be. Fancy having to pay the full price asked because the order is pressing and he has been given carte blanche by this client!
That evening the two brokers are seen to dine tete-a-tete at Voisin’s. The next day Madame Veuve Moulin’s concierge shakes his head knowingly when takes up for the first time to her tiny flat a bouquet of flowers too large to squeeze through the narrow doorway.
From that day bouquets almost of the dimensions of cart wheels arrive everyday for nearly three weeks. Of a sudden they cease coming, and Madame Veuve Moulin that was ventures a faintly cynical remark across the breakfast table. Monsieur Blisky just lowers his morning paper and says, “Cherie, soyez raisonnable. Am I not now paying for cabbages and peas for two?”
Published by Sheridan House, New York
1937
Sheridan House writes:
Lucky is the man whose life has been the pursuit of beauty and adventure. Louis Kornitzer, one of the great rare peal dealers of the world, is that man.
His autobiography, The Pearl Dealer, is one of the great autobiographies of our time—if not of all time—for it shows that a businessman may be an artist, an adventurer, a philosopher, and that one need not be an Axel Munthe, a Victor Heiser, or a Vincent Sheean to have lived a full, exciting, and intelligent life.
With the “world as his oyster” our author set out from London for the wide open, two gun pearl fishing town of Broome, Australia…from there to Sulu and Zamboanga (where the monkeys have no tails), when Black Jack Pershing was earning his gold stars chasing Moros into the hills----then to Hong Kong, where we get an inside view of the business ways for which the heathen Chinee is peculiar…from an odyssey through the Far East he sails back to London and Paris, where the great pearl traders nonchalantly toss about king’s ransoms in little tissue paper envelopes and where the author regales us with sophisticated tales of the vanity of men and the beauty of women.
A third division of this book is a short encyclopedia of pearl lore, which contains for the first time the intimate secrets of a pearl connoisseurs in their judgment of these subtle and moon-like gems.
Among the hundreds of good stories, anecdotes, and observations that tumble out of Kornitzer’s merry pages are those of the monkey who knew how many peanuts he could buy for a centavo…the Chinese clerk whose self-invented system of phonetics could record any sound from the spoken word to the flutter of a leaf…the dispute between the Canton vendor or roast cockroaches and the customer who purchased one of these dainties for a cash (about 1/20 of a cent) and then complained of its quality…the pearl dealer who was ruined by his honesty…Pigott, whose sense of humor saved his head…and the strange adventures of those wizards of skill, the pearl doctors.
Here you have an amusing record of a full life: wit, philosophy, anecdote, business experience, beauty, adventure, history, science and art.
The Pearl Trader is a human document of engrossing interest. There is not a single dull paragraph in its 384 pages.
About Louis Kornitzer
Author of The Pearl Trader
As a boy he sorted dirty seed pearls brought from the ghettos of Poland to his father’s shop…as a young man he learned the wiles of trading in the great gem marts of the world….as a man he traded with the wild Sea Dyaks of the Celebes, Mandarins with the culture of thousand of years a their finger tips, and Connemera Curraghmen who knew their values as well as the brokers of Maiden Lane.
He has left little or nothing out of his crowded life story, The Pearl Trader…you must read this book to savor fully one of the great personalities of our time.
The Pearl Merchants of Paris
Louis Kornitzer writes:
For a long time, a very long time, Paris has been the center of the pearl trade. The reason for this escapes me, unless it is that the many wealthy foreigners who visit it spend their money there more readily than they do anywhere else.
That, of course, would only be partial explanation, as would also the fact that the French gold and silversmiths are more than ordinarily skilled workers in precious metals. But as most of the important pearl fishing stations are situated in British possessions or adjoining them, and as nine-tenths of the pearls fished all over the world are consigned to London bankers and import houses, it is rather strange that Paris and not London should have become the great distributing center for this gem.
Within the last fifty years that part of the Rue Lafayette which runs from the Gare du Nord to within a few paces of the Grand Opera House has attracted numerous pearl merchants and brokers, whose offices are located in that thoroughfare. The Rue Lafayatte is to Pars what Hatton Garden is to London and Maiden Lane to New York—the headquarters of the trade in precious stones and pearls.
In any of these three thoroughfares there are to be seen throughout the whole year, irrespective of the season, and in practically all weathers short of tropical downpour or a hurricane, groups of men, for the most part sallow-complexioned, beak-nosed, and falcon-eyed, standing on the pavement or in the gutter, so that is sometimes difficult to pass. It is a hundred to one that these are more than fresh air fiends—that they are dealers or brokers in precious stones. Those who have a more refined appearance are undoubtedly the handlers of pearls. It would indeed be strange if the constant communion with the queen of gem had no refining influence.
If you are interested to discover which of them are dealers and which are brokers, you have only to peer into their faces. The haggard and pale, the worried-looking ones, those are the dealers. The sleekly-complacent and jesting ones are the brokers. Must I explain? The dealer has to take and give credit. Any error of judgment when appraising goods is upon his own head and his is the entire risk. But the broker is merely the go-between. Heads or tails, he wins. He obtains a brokerage from both buyer and seller, 1 per cent from either side, and the merchants have to pay him whether they register a gain or a loss.
You may wonder why, since the dealers know of each other’s existence, they do not trade directly and thus save the brokerage. They would certainly do so if they could, because brokerage is stiff tax, and no merchant is keen on curtailing his own profit or increasing his charges. But they cannot dispense with the broker. They have to tolerate him as the shark tolerates the pilot fish ( I trust the comparison will not be carried to extreme lengths).
The broker touts for business. He knows, or ought to know, the requirements of nearly everybody with whom he comes in contact. He is a kind of marriage broker. He is expected to praise the bride-to-be (vendor’s goods) and to extol the merits of the future bridegroom (the solvency of the buyer). He is a pimp of sorts, too, if you like. Yet it is to be acknowledged that he often acts the imperial judge and holds the scales of fairly even, and that more often than not he is worthy of his hire.
No, they are not all Jews, these Paris pearl- merchants and brokers. Many are Armenians, Syrians, Arabs, Parsees, Hindus, with a sprinkling of Neapolitans and Catalans and an odd Frenchman or two.
The appearance of many of them is not prepossessing. I grant you, and perhaps we would not be inclined to trust some of them out of our sight with a one cent stamp. Yet in some ways these men’s word is their bond. Their nod is as good as stamped agreement. Their verbal offer is binding. Parcels of pearls or other gems are handed from trader to trader and by them to brokers back and forth in an intricate chain, without acknowledgment in writing, without a receipt of any kind, and often without being checked over for contents. It is taken for granted by all concerned that the details of numbers and weights are correct and precisely as recorded on the wrappers containing the valuable merchandise.
Coming and going, there is implicit trust and almost child-like faith on this particular side of the business. Of chicanery there is plenty, as you will hear, but not in the important matter of ‘handing-round’ for sale, upon which the whole trade depends. Woe to the member of the closed circle, therefore, who betrays the confidence, reposed in him. His name is besmirched for evermore, and the gutter is his lot. The crook in the jewel trade is not honest because he loves virtue, but because he must be so.
The trade has peculiar customs, and by some of them the skinflint or the rogue has to abide, even when it hurts his pockets. There are, for example, times when a bargain, like a good steed, can be made to carry two.
Look at this particular group of four men standing on the curb of the Rue Lafayette. Each is acting according to his lights and his nature, and all are quite unselfconscious, for they do not know that thirty years later we shall be looking at them.
Of the four, the two well-groomed and prosperous-looking men are dealers; Senor Lopez, a Portuguese Jew, and Herr Ohnstadt, a naturalized Frenchman. Third is small shopkeeper from the Faubourg St.Germain. He is French from the tip of goatee to his prejudice against everything non-Gallic.
The fourth man does not know his own nationality. Neither Russians nor Poles will acknowledge him, but each try to wish him on to the other party. Meanwhile the French Government, which is patient with the alien sojourning in the midst, cannot send him over the frontier, because during forty years residence he has behaved himself properly. But he has never bothered about taking out naturalization papers to make himself Frenchman, and now he is a failure and may at any moment become a public charge, which is a crime in any country. Unhappy man! In this age of aggressive nationalism the life of an international no-account is not a happy one.
Ten short years ago he meant to retire and live on his rentes. Then he was prosperous. But he delayed too long, and the lean times came. When he could no longer afford to advise his business friends of his intended retirement—the postage being such a heavy item—he merely had to remain n harness. What else was there to do? And now he has no office; but the curb is a good place. Que voulez-vous? Offices are often stuffy, but here under God’s open sky one may breathe freely and catch one’s clients on the wing. By leave of the sergent de ville one may meet and foregather with old cronies, laugh at their stale jokes, until the voice of law and order says, ‘Pass along, Messieurs, pass along.’
Sometimes, though, not often, Nitchevitch’s bleary eyes are made to overflow with salty happiness when an old acquaintance nudges him en passant. Oh, it is good to be taken notice of when one gets old and—who says poor? No, no! We refuse to have that world applied to an old member of an exclusive circle who black coat shows not a single speck of dust and whose boots shine, veritably, like black pearls.
Sometimes, and generally after his wife has pointed to an empty larder, he may have to muster sufficient aggressiveness to squeeze himself into a deal. There is not always the opportunity, but it is going to present itself today even as we watch.
The French shopkeeper of the Rue du Bac in the Faubourg St.Germain is offering to Senor Lopez a fine secondhand jewel, a snuff box in solid gold exquisitely chased and set with Indian emeralds and rubies, and bordered with rose diamonds. Senor Lopez knows a genuine antique and scents a bargain. He really should not discuss the price at all, since it is being offered so cheaply, but pay what is asked; but from force of habit he fences for a rebate. However, at last, seeing that the deal is attracting the attention of the other dealers, he pulls out a roll of bedraggled notes and begins reluctantly to peel off the appropriate number.
But before the notes have had time to pass from buyer to seller, he who had contemplated retirement ten years ago on his own fat, and has now nothing but a couple of francs in his pocket, sings out, “Monsieur Lopez, I am in this deal with you up to a ten per cent risk!”
The Portuguese Jew looks daggers. But he can do nothing. Custom is rigid on the point. He knows well that there is no way of shaking off the infliction of an associate who is not going to invest a centime, who cannot contribute his share if a loss were to eventuate, and who will presently state how much he must be paid to be got rid of.
By and by, before the sun has gone down, Senor Lopez will offer Monsieur Nitchevitch so many hundred of francs to surrender his mythical interest. The latter, you might think, will be satisfied with any kind of offer, but not he. He will drive a desperate bargain, thinking all the time of the nagging wife at home and her empty larder. Finally, however, he will surrender his claim with a generous sweep of the hand, clutch nervously at the billes de cents, and make off to his obscure and mysterious abode.
You would perhaps call this blackmail. Business, strictly speaking, it is not. But it is the custom. On the whole, however, dealing in gems is a matter of diamond cut diamond and devil take the loser. Take the romantic tale of Jules Grun, Blisky, and Madame Moulin, depicting love among the pearl dealers.
It is really fortunate for you that I happen to know Jules Grun, the millionaire pearl merchant. Thus I take you to his office in that building on the other side of the street. Up one flight of stairs only, so we need not bother, about that narrow-chested wheezy lift. Here we are. Fine waiting room, luxurious carpets, handsome furniture, and the coziest of armchairs to make callers forget the painful suspense of waiting. But we will not sit down. Taking advantage of our cloak of darkness, we got right into the inner office and look about us.
Of the three people at work here you need take not notice at all of two. They are mere paid servants, nobodies. The one person who matters here, for he proclaims it often enough, is Jules Grun himself. There he sits, behind the large flat desk, bald-headed, full-faced, ruddy, and prosperous.
Besides ourselves there is another visitor, a visible one. He is an ordinary-looking person, Blisky by name, a broker. Everybody in the trade knows Blisky. Between Grun, the merchant, and Blisky, the broker, there lie on the table three bunches of oriental pearls. They have already given rise to great deal of talk before we came on the scence, but Blisky is still talking in the manner of brokers the world over, glibly and with serpentine guile, and there is nothing to show that he will ever stop.
Grun talks little. He contents himself with taking up one bunch after another, scrutinizing it carefully through a powerful lens, for the tenth time perhaps. Then he shakes his head from side to side, as pearl merchants do who are interested but intend to conceal it. Finally, he pushes them all together and towards the broker and grunts, “My first bid, Blisky, was more than generous. They are not worth more. You are foolish not to pass my offer on to your client.”
“I am very sorry, Monsieur Grun,” says Blisky, “but I have too much respect for myself to face my client with such a poor offer. He is temporarily embarrassed, as I told you, but there are limits.”
“People who are temporarily embarrassed for ready money should not deal in pearls,” says Grun pompously.
“Maybe yes and maybe no,” says Blisky in a huffed tone, “but as it is not my business to tell my clients what to do and what not to do, that gets us nowhere. You are acting crazy when you allow these bunches to slip through your fingers like this. I suppose you are so rich already that you absolutely refuse to make more money! You are getting to be such a hard nut, too, Monsieur, I warn you, that most brokers are scared to come to you. Were it not that four hundred thousand francs are not everyone’s money, I should not sit here now, be sure. But where in Paris is there another dealer who can lay his hands on so much cash at a moment’s notice?”
“But that is the reason, my dear Blisky, why I want to buy at my own price!”
Just then a clerk enters the room and hands the merchant a slip of paper. He glances at it and says, “Show the lady in,” and turning to the broker adds, “If you care to wait in the next room, I may have another look presently.”
There enters briskly, brushing past the retiring Blisky, a woman middle-aged, good-looking and self-possessed. With business-like directness she states her requirements immediately. A client of hers needs so many pearls of such a size and quality for three sautoirs. If Monsieur has them in stock, she can vouch for a sure sale and spot cash.
Grun almost gasps, but not quite. Strange coincidence! The fellow in the next room has the very thing tucked away in his leather wallet. What luck that he asked him to wait!
“Madame Moulin!,” he says impressively, “I believe I can accommodate your client, but the goods are out at the moment. If you will give me an hour, I will recall them and you can submit them to your client.”
Blisky, however, though a decent fellow and no eavesdropper, has happened to hear all this. The door has been left ajar by accident, and now he knows what is afoot. He decides he is tired of waiting, in spite of the luxuriousness of the waiting room and the comfort of the easy chair. He let himself out and travels down in the groaning lift—for he never believes in walking if he can ride.
He has not long to wait in the street below. Voiture! Voiture! There they go, Madame Moulin and Blisky, as fast as the crock in the shafts of the creaking four wheeler will take them, towards the glittering facades of the Rue de la Paix. The jeweler with whom they are presently closeted is in the worst position a jeweler can possibly be. Fancy having to pay the full price asked because the order is pressing and he has been given carte blanche by this client!
That evening the two brokers are seen to dine tete-a-tete at Voisin’s. The next day Madame Veuve Moulin’s concierge shakes his head knowingly when takes up for the first time to her tiny flat a bouquet of flowers too large to squeeze through the narrow doorway.
From that day bouquets almost of the dimensions of cart wheels arrive everyday for nearly three weeks. Of a sudden they cease coming, and Madame Veuve Moulin that was ventures a faintly cynical remark across the breakfast table. Monsieur Blisky just lowers his morning paper and says, “Cherie, soyez raisonnable. Am I not now paying for cabbages and peas for two?”
Wednesday, January 17, 2007
Business World
Warren Edward Buffett, CEO, Berkshire Hathaway writes:
'In the business world, the rearview mirror is always clearer than the windshield.'
'In the business world, the rearview mirror is always clearer than the windshield.'
Star Beryl
Star beryl is often brown in color and display a weak 6 rayed star. The stone may look very similar to black star sapphire. In beryl, the star effect is not from sets of needles or needle-like inclusions, but instead from plates of ilmenite and hematite, which are oriented in certain positions parallel to the basal plane. These plates may also give the stone its dark brown color; if it is viewed parallel to the plates, clear transparent areas are seen.
Another feature is the hexagonal shield which is seen at the point where the rays intersect. This unique feature makes it easy to separate it from other star stones. The characteristic inclusions seen in star beryl are extremely thin plate-like dendrites of ilmenite (black) and hematite (orange) on the basal plane.
Another feature is the hexagonal shield which is seen at the point where the rays intersect. This unique feature makes it easy to separate it from other star stones. The characteristic inclusions seen in star beryl are extremely thin plate-like dendrites of ilmenite (black) and hematite (orange) on the basal plane.
How To Separate Frequently Encountered Pink Stones
- Visual observation: (10x lens) Look for color, luster, cut, doublet/triplet junctions, if any.
- Determine optic character: Single refractive (SR) / Double refractive (DR) / Anomalous Double refractive (ADR) / Aggregate (AGG).
- Spectrum: Many pink stones may have diagnostic spectrum.
- Microscope: Inclusions may be diagnostic, but look for inclusions that differentiate natural and synthetic, doublet / triplet.
- Dichroscope: Different cutting orientations of natural and synthetic corundum may be revealed by dichroscope.
- Fluorescence: Look under shortwave and longwave for diagnostic colors.
- Immersion cell: Use immersion cell and high refractive index liquid to separate doublets/triplets.
- Refractometer: Confirm spectroscope reading with refractometer.
The pink stones, which may resemble one another in appearance and values, are:
Scapolite (group)
- Hardness: 6
- Specific gravity: 2.50 – 2.71
- Refractive index: 1.54 – 1.58
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.009/26
- Other points: Inclusions, color, R.I
Pink Beryl
- Hardness: 7.5
- Specific gravity: 2.80 (average)
- Refractive index: 1.57 – 1.58
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.006
- Other points: Inclusions, color. Pink beryl may be treated. Pink beryl may look like Kunzite or glass. Gem quality stones are relatively clean. Analytical techniques may be required to detect treatments.
Tourmaline
- Hardness: 7
- Specific gravity: 3.03
- Refractive index: 1.62 – 1.64
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.018
- Other points: Inclusions, color, luster. Tourmalines may be treated. Pink tourmaline may look like pink sapphire, pink spinel, pink beryl or glass. Gem quality stones are relatively clean. Analytical techniques may be required to detect treatments.
Pink Andalusite
- Hardness: 7.5
- Specific gravity: 3.18
- Refractive index: 1.63 – 1.64
- Optic sign: Biaxial negative
- Birefringence: DR; 0.010
- Other points: Color, pleochroism, luster.
Topaz
- Hardness: 8
- Specific gravity: 3.53
- Refractive index: 1.63 – 1.64
- Optic sign: Biaxial positive
- Birefringence: DR; 0.008
- Other points: Color, luster. Topaz may be treated. Pink topaz may look like pink sapphire, pink spinel, pink beryl or glass. Gem quality stones are relatively clean. Analytical techniques may be required to detect treatments.
Kunzite
- Hardness: 6.5
- Specific gravity: 3.18
- Refractive index: 1.66 – 1.68
- Optic sign: Biaxial positive
- Birefringence: DR; 0.015
- Other points: Pleochroism, cleavage, inclusions, color (may fade). Kunzite may be treated. Kunzite may look like pink beryl (morganite) or glass. Gem quality stones are relatively clean. Analytical techniques may be required to detect treatments.
Spinel
- Hardness: 8
- Specific gravity: 3.60
- Refractive index: 1.718
- Optic sign: SR
- Birefringence: -
- Other points: Color, spectrum, inclusions. Pink spinel may look like pink sapphire, pink tourmaline, kunzite, pink beryl or glass.
Taaffeite
- Hardness: 8
- Specific gravity: 3.60
- Refractive index: 1.717 – 1.723
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.004
- Other points: Rare, color (usually blue purple).
Garnet (rhodolite)
- Hardness: 7.5
- Specific gravity: 3.78 (average)
- Refractive index: 1.75 (average)
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Color, spectrum. Rhodolite may look like pink to purplish red sapphire, pink to purplish red spinel or glass.
Pink Sapphire
- Hardness: 9
- Specific gravity: 4
- Refractive index: 1.76 – 1.77 (average)
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.008
- Other points: Color, inclusions (use microscope to separate natural vs synthetic), fluorescence. Pink sapphire may be treated. Pink sapphire may look like pink tourmaline, pink spinel, kunzite, pink beryl or glass. Gem quality stones are relatively clean. Analytical techniques may be required to detect treatment.
Synthetic sapphire
- Hardness: 9
- Specific gravity: 4
- Refractive index: 1.76 – 1.77 (average)
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.008
- Other points: Color, inclusions (use microscope to distinguish flux and hydrothermal).
Synthetic cubic zirconia
- Hardness: 8.5
- Specific gravity: 5.65 +
- Refractive index: 2.15 +
- Optic sign: SR
- Birefringence: -
- Other points: negative refractive index, luster, color, orange flash on the pavilion, dispersion.
Diamond
- Hardness: 10
- Specific gravity: 3.52
- Refractive index: 2.42
- Optic sign: SR/ADR
- Birefringence: -
- Other points: negative refractive index, color, luster, inclusions, spectrum. Pink diamond is quite rare and expensive.
Glass
- Hardness: 5.5
- Specific gravity: 3.70
- Refractive index: 1.60-1.66
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Soft, color, inclusions (gas bubbles), luster, spectrum
- Determine optic character: Single refractive (SR) / Double refractive (DR) / Anomalous Double refractive (ADR) / Aggregate (AGG).
- Spectrum: Many pink stones may have diagnostic spectrum.
- Microscope: Inclusions may be diagnostic, but look for inclusions that differentiate natural and synthetic, doublet / triplet.
- Dichroscope: Different cutting orientations of natural and synthetic corundum may be revealed by dichroscope.
- Fluorescence: Look under shortwave and longwave for diagnostic colors.
- Immersion cell: Use immersion cell and high refractive index liquid to separate doublets/triplets.
- Refractometer: Confirm spectroscope reading with refractometer.
The pink stones, which may resemble one another in appearance and values, are:
Scapolite (group)
- Hardness: 6
- Specific gravity: 2.50 – 2.71
- Refractive index: 1.54 – 1.58
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.009/26
- Other points: Inclusions, color, R.I
Pink Beryl
- Hardness: 7.5
- Specific gravity: 2.80 (average)
- Refractive index: 1.57 – 1.58
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.006
- Other points: Inclusions, color. Pink beryl may be treated. Pink beryl may look like Kunzite or glass. Gem quality stones are relatively clean. Analytical techniques may be required to detect treatments.
Tourmaline
- Hardness: 7
- Specific gravity: 3.03
- Refractive index: 1.62 – 1.64
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.018
- Other points: Inclusions, color, luster. Tourmalines may be treated. Pink tourmaline may look like pink sapphire, pink spinel, pink beryl or glass. Gem quality stones are relatively clean. Analytical techniques may be required to detect treatments.
Pink Andalusite
- Hardness: 7.5
- Specific gravity: 3.18
- Refractive index: 1.63 – 1.64
- Optic sign: Biaxial negative
- Birefringence: DR; 0.010
- Other points: Color, pleochroism, luster.
Topaz
- Hardness: 8
- Specific gravity: 3.53
- Refractive index: 1.63 – 1.64
- Optic sign: Biaxial positive
- Birefringence: DR; 0.008
- Other points: Color, luster. Topaz may be treated. Pink topaz may look like pink sapphire, pink spinel, pink beryl or glass. Gem quality stones are relatively clean. Analytical techniques may be required to detect treatments.
Kunzite
- Hardness: 6.5
- Specific gravity: 3.18
- Refractive index: 1.66 – 1.68
- Optic sign: Biaxial positive
- Birefringence: DR; 0.015
- Other points: Pleochroism, cleavage, inclusions, color (may fade). Kunzite may be treated. Kunzite may look like pink beryl (morganite) or glass. Gem quality stones are relatively clean. Analytical techniques may be required to detect treatments.
Spinel
- Hardness: 8
- Specific gravity: 3.60
- Refractive index: 1.718
- Optic sign: SR
- Birefringence: -
- Other points: Color, spectrum, inclusions. Pink spinel may look like pink sapphire, pink tourmaline, kunzite, pink beryl or glass.
Taaffeite
- Hardness: 8
- Specific gravity: 3.60
- Refractive index: 1.717 – 1.723
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.004
- Other points: Rare, color (usually blue purple).
Garnet (rhodolite)
- Hardness: 7.5
- Specific gravity: 3.78 (average)
- Refractive index: 1.75 (average)
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Color, spectrum. Rhodolite may look like pink to purplish red sapphire, pink to purplish red spinel or glass.
Pink Sapphire
- Hardness: 9
- Specific gravity: 4
- Refractive index: 1.76 – 1.77 (average)
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.008
- Other points: Color, inclusions (use microscope to separate natural vs synthetic), fluorescence. Pink sapphire may be treated. Pink sapphire may look like pink tourmaline, pink spinel, kunzite, pink beryl or glass. Gem quality stones are relatively clean. Analytical techniques may be required to detect treatment.
Synthetic sapphire
- Hardness: 9
- Specific gravity: 4
- Refractive index: 1.76 – 1.77 (average)
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.008
- Other points: Color, inclusions (use microscope to distinguish flux and hydrothermal).
Synthetic cubic zirconia
- Hardness: 8.5
- Specific gravity: 5.65 +
- Refractive index: 2.15 +
- Optic sign: SR
- Birefringence: -
- Other points: negative refractive index, luster, color, orange flash on the pavilion, dispersion.
Diamond
- Hardness: 10
- Specific gravity: 3.52
- Refractive index: 2.42
- Optic sign: SR/ADR
- Birefringence: -
- Other points: negative refractive index, color, luster, inclusions, spectrum. Pink diamond is quite rare and expensive.
Glass
- Hardness: 5.5
- Specific gravity: 3.70
- Refractive index: 1.60-1.66
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Soft, color, inclusions (gas bubbles), luster, spectrum
Star Stone Imitations
The appearance of asterism can be produced on almost any transparent cabochon by cutting hundreds of fine grooves into its base. The grooves are usually cut in three directions with a diamond tool, and a mirror or a mirror-like coating is attached to the back. This creates a 6-rayed star of reasonable intensity. The mirror on the back of the stone and the appearance of the star is quite easy to identify. Usually synthetic gemstones are used in this imitation.
The most effective imitation star stone is made by placing a hollow cabochon of synthetic corundum over a piece of asteriated natural corundum, and then closing the back with a third piece. Once assembled and set in a piece of jewelry the girdle plane can be hidden by the setting. Sometimes a slice of black star corundum is glued to the back of the cabochon of synthetic corundum. The assembled stones can easily identified by their separation planes.
Another good imitation star stone is made up of a white opaque glass which is pressed into a mold to form cabochon with six raised ridges on the crown. The ridged cabochon is then coated with a thin layer of deep blue glaze which barely covers the ridges. The finished stone has a very similar appearance to a natural star sapphire with the star on or just below the surface. The stones are easy to identify because the stars does not move or roll across the surface when the stone is turned. Physical constants are typical of glass, not corundum.
Star diopside and star enstatite are two less-known inexpensive stones, which are often confused with one another. Both may display four rayed stars which meet at almost 90º. The reason for confusion is that they are frequently mixed into the same lots and sold as black stars. Star diopside usually display very sharp star, while enstatite may show weaker more diffused star and a unique bronzy sheen. Enstatite may also display eight rayed star.
The most effective imitation star stone is made by placing a hollow cabochon of synthetic corundum over a piece of asteriated natural corundum, and then closing the back with a third piece. Once assembled and set in a piece of jewelry the girdle plane can be hidden by the setting. Sometimes a slice of black star corundum is glued to the back of the cabochon of synthetic corundum. The assembled stones can easily identified by their separation planes.
Another good imitation star stone is made up of a white opaque glass which is pressed into a mold to form cabochon with six raised ridges on the crown. The ridged cabochon is then coated with a thin layer of deep blue glaze which barely covers the ridges. The finished stone has a very similar appearance to a natural star sapphire with the star on or just below the surface. The stones are easy to identify because the stars does not move or roll across the surface when the stone is turned. Physical constants are typical of glass, not corundum.
Star diopside and star enstatite are two less-known inexpensive stones, which are often confused with one another. Both may display four rayed stars which meet at almost 90º. The reason for confusion is that they are frequently mixed into the same lots and sold as black stars. Star diopside usually display very sharp star, while enstatite may show weaker more diffused star and a unique bronzy sheen. Enstatite may also display eight rayed star.
Tuesday, January 16, 2007
How To Separate Frequently Encountered Red Stones
- Visual observation: (10x lens) Look for color, luster, cut, doublet/triplet junctions, if any.
- Determine optic character: Single refractive (SR) / Double refractive (DR) / Anomalous Double refractive (ADR) / Aggregate (AGG).
- Spectrum: Many red stones may have diagnostic spectrum.
- Microscope: Inclusions may be diagnostic, but look for inclusions that differentiate natural and synthetic, doublet / triplet.
- Dichroscope: Different cutting orientations of natural and synthetic corundum may be revealed by dichroscope.
- Fluorescence: Look under shortwave and longwave for diagnostic colors.
- Immersion cell: Use immersion cell and high refractive index liquid to separate doublets/triplets.
- Refractometer: Confirm spectroscope reading with refractometer.
The red stones, which may resemble one another in appearance and values, are:
Red Beryl
- Hardness: 7.5
- Specific gravity: 2.70 (average)
- Refractive index: 1.57 – 1.58
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.006
- Other points: Inclusions, color. There are many treated stones in the gem market. Analytical techniques may be required to detect treatments.
Tourmaline
- Hardness: 7
- Specific gravity: 3.03
- Refractive index: 1.62 – 1.64
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.018
- Other points: Inclusions, color, pleochroism. There are many treated stones in the gem market. Many gem quality tourmalines are relatively clean. Analytical techniques may be required to detect treatments.
Topaz
- Hardness: 8
- Specific gravity: 3.53
- Refractive index: 1.63 – 1.64
- Optic sign: Biaxial positive
- Birefringence: DR; 0.008
- Other points: Inclusions, color (pink stones may be confused for pink sapphires). There are many treated stones in the market. Most gem quality stones are relatively clean. Analytical techniques may be required to detect treatments.
Spinel
- Hardness: 8
- Specific gravity: 3.60
- Refractive index: 1.718
- Optic sign: SR
- Birefringence: -
- Other points: Inclusions, color, spectrum.
Garnet (pyrope)
- Hardness: 7.5
- Specific gravity: 3.78 (average)
- Refractive index: 1.75 (average)
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Inclusions, color (may be confused for Thai ruby / synthetic ruby), spectrum.
Garnet (almandine)
- Hardness: 7.5
- Specific gravity: 4.10 (average)
- Refractive index: 1.78 (average)
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Inclusions, color (may be confused for Thai ruby / synthetic ruby), spectrum.
Ruby
- Hardness: 9
- Specific gravity: 4 (average)
- Refractive index: 1.76 – 1.77 (average)
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.008
- Other points: Inclusions, color, spectrum (use microscope to separate natural vs synthetic). There are many treated stones in the gem market. Analytical techniques may be required to detect treatments.
Synthetic Ruby
- Hardness: 9
- Specific gravity: 4 (average)
- Refractive index: 1.76 – 1.77 (average)
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.008
- Other points: Inclusions, color, spectrum (use microscope to differentiate flux and hydrothermal). Gem quality stones are relatively clean.
Synthetic red cubic zirconia
- Hardness: 8.5
- Specific gravity: 5.65 +
- Refractive index: 2.15 +
- Optic sign: SR
- Birefringence: -
- Other points: negative refractive index, luster, color, orange flash on the pavilion, dispersion. Gem quality stones are relatively clean.
Red Zircon
- Hardness: 7.5
- Specific gravity: 4.69
- Refractive index: 1.93 – 1.99
- Optic sign: Uniaxial positive
- Birefringence: DR; 0.059
- Other points: Inclusions, color, spectrum, doubling of the back facets, dispersion, luster, negative refractive index reading. There are many treated stones in the gem market. Analytical techniques may be required to detect treatments.
Red Diamond
- Hardness: 10
- Specific gravity: 3.52
- Refractive index: 2.42
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Rare, negative refractive index reading, inclusions, luster, spectrum, dispersion. There are many treated stones in the market. Most treated diamonds are relatively clean. Analytical techniques may be required to detect treatments.
Synthetic red diamond
- Hardness: 10
- Specific gravity: 3.52
- Refractive index: 2.42
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Negative refractive index reading, color, inclusions, luster, spectrum, fluorescence. Synthetic diamonds are produced by the high pressure high temperature method. Gem quality stones are relatively clean. Analytical techniques may be required to identify the stones.
Glass
- Hardness: 5.5
- Specific gravity: 3.70
- Refractive index: 1.60 – 1.66
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Soft, inclusions (gas bubbles), color.
Assembled Stones
Doublets / Triplets
Corundum (natural crown / synthetic base)
Other points: Immersion (Look for differences in color and luster between the sections).
Garnet topped doublet (glass)
- Refractive index: 1.76 +
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Look for differences in color and luster between the sections, gas bubbles).
Synthetic spinel soude (spinel / spinel)
- Refractive index: 1.728
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Look for differences in color and luster between the sections, gas bubbles).
- Determine optic character: Single refractive (SR) / Double refractive (DR) / Anomalous Double refractive (ADR) / Aggregate (AGG).
- Spectrum: Many red stones may have diagnostic spectrum.
- Microscope: Inclusions may be diagnostic, but look for inclusions that differentiate natural and synthetic, doublet / triplet.
- Dichroscope: Different cutting orientations of natural and synthetic corundum may be revealed by dichroscope.
- Fluorescence: Look under shortwave and longwave for diagnostic colors.
- Immersion cell: Use immersion cell and high refractive index liquid to separate doublets/triplets.
- Refractometer: Confirm spectroscope reading with refractometer.
The red stones, which may resemble one another in appearance and values, are:
Red Beryl
- Hardness: 7.5
- Specific gravity: 2.70 (average)
- Refractive index: 1.57 – 1.58
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.006
- Other points: Inclusions, color. There are many treated stones in the gem market. Analytical techniques may be required to detect treatments.
Tourmaline
- Hardness: 7
- Specific gravity: 3.03
- Refractive index: 1.62 – 1.64
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.018
- Other points: Inclusions, color, pleochroism. There are many treated stones in the gem market. Many gem quality tourmalines are relatively clean. Analytical techniques may be required to detect treatments.
Topaz
- Hardness: 8
- Specific gravity: 3.53
- Refractive index: 1.63 – 1.64
- Optic sign: Biaxial positive
- Birefringence: DR; 0.008
- Other points: Inclusions, color (pink stones may be confused for pink sapphires). There are many treated stones in the market. Most gem quality stones are relatively clean. Analytical techniques may be required to detect treatments.
Spinel
- Hardness: 8
- Specific gravity: 3.60
- Refractive index: 1.718
- Optic sign: SR
- Birefringence: -
- Other points: Inclusions, color, spectrum.
Garnet (pyrope)
- Hardness: 7.5
- Specific gravity: 3.78 (average)
- Refractive index: 1.75 (average)
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Inclusions, color (may be confused for Thai ruby / synthetic ruby), spectrum.
Garnet (almandine)
- Hardness: 7.5
- Specific gravity: 4.10 (average)
- Refractive index: 1.78 (average)
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Inclusions, color (may be confused for Thai ruby / synthetic ruby), spectrum.
Ruby
- Hardness: 9
- Specific gravity: 4 (average)
- Refractive index: 1.76 – 1.77 (average)
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.008
- Other points: Inclusions, color, spectrum (use microscope to separate natural vs synthetic). There are many treated stones in the gem market. Analytical techniques may be required to detect treatments.
Synthetic Ruby
- Hardness: 9
- Specific gravity: 4 (average)
- Refractive index: 1.76 – 1.77 (average)
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.008
- Other points: Inclusions, color, spectrum (use microscope to differentiate flux and hydrothermal). Gem quality stones are relatively clean.
Synthetic red cubic zirconia
- Hardness: 8.5
- Specific gravity: 5.65 +
- Refractive index: 2.15 +
- Optic sign: SR
- Birefringence: -
- Other points: negative refractive index, luster, color, orange flash on the pavilion, dispersion. Gem quality stones are relatively clean.
Red Zircon
- Hardness: 7.5
- Specific gravity: 4.69
- Refractive index: 1.93 – 1.99
- Optic sign: Uniaxial positive
- Birefringence: DR; 0.059
- Other points: Inclusions, color, spectrum, doubling of the back facets, dispersion, luster, negative refractive index reading. There are many treated stones in the gem market. Analytical techniques may be required to detect treatments.
Red Diamond
- Hardness: 10
- Specific gravity: 3.52
- Refractive index: 2.42
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Rare, negative refractive index reading, inclusions, luster, spectrum, dispersion. There are many treated stones in the market. Most treated diamonds are relatively clean. Analytical techniques may be required to detect treatments.
Synthetic red diamond
- Hardness: 10
- Specific gravity: 3.52
- Refractive index: 2.42
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Negative refractive index reading, color, inclusions, luster, spectrum, fluorescence. Synthetic diamonds are produced by the high pressure high temperature method. Gem quality stones are relatively clean. Analytical techniques may be required to identify the stones.
Glass
- Hardness: 5.5
- Specific gravity: 3.70
- Refractive index: 1.60 – 1.66
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Soft, inclusions (gas bubbles), color.
Assembled Stones
Doublets / Triplets
Corundum (natural crown / synthetic base)
Other points: Immersion (Look for differences in color and luster between the sections).
Garnet topped doublet (glass)
- Refractive index: 1.76 +
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Look for differences in color and luster between the sections, gas bubbles).
Synthetic spinel soude (spinel / spinel)
- Refractive index: 1.728
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Look for differences in color and luster between the sections, gas bubbles).
How To Observe Fluorescence Under Ultraviolet Light
- Make observations in a darkened environment. Allow a few moments for your eyes to adjust to the darkness in order to be able to detect weak fluorescence.
- Place the stone (s) on a non-reflective background directly under the light source. In order to be sure that the color noted is actually a fluorescent effect, and not a reflection of the Ultraviolet light source from the facets of the stone, always position the stone in several directions.
- Look for a dull powdery color on the surface of the stone (ignore color due to the surface reflection of visible light and from light leaking into the test unit). Record, in both long and short wave ultraviolet light, the reaction of the stone as Inert, Weak, or Strong fluorescence and note the color.
Note: If the stone fluoresces strongly, look for phosphorescence (after-glow).
- Observe the crown, pavilion and girdle of the stone, as it may be a doublet or a triplet.
- Place the stone (s) on a non-reflective background directly under the light source. In order to be sure that the color noted is actually a fluorescent effect, and not a reflection of the Ultraviolet light source from the facets of the stone, always position the stone in several directions.
- Look for a dull powdery color on the surface of the stone (ignore color due to the surface reflection of visible light and from light leaking into the test unit). Record, in both long and short wave ultraviolet light, the reaction of the stone as Inert, Weak, or Strong fluorescence and note the color.
Note: If the stone fluoresces strongly, look for phosphorescence (after-glow).
- Observe the crown, pavilion and girdle of the stone, as it may be a doublet or a triplet.
Trapiche Emerald
Trapiche emeralds consist of emerald crystals which contain inclusions of a mixture of albite feldspar and beryl. These inclusions radiate out from a hexagonal core to form a six spoke pattern.
Trapiche emeralds are unique to the Colombian deposits, but similar crystals have been found in Brazil and elsewhere. Trapiche is the Spanish word for cog wheels once used to crush sugarcane. If certain types of trapiche emeralds are cut as cabochons with the base perpendicular to the crystallographic axis of the crystal, a hexagonal chatoyancy may be seen. It is due to fibrous inclusions contained in each of the six spokes that radiate outward from the core.
Trapiche emeralds are unique to the Colombian deposits, but similar crystals have been found in Brazil and elsewhere. Trapiche is the Spanish word for cog wheels once used to crush sugarcane. If certain types of trapiche emeralds are cut as cabochons with the base perpendicular to the crystallographic axis of the crystal, a hexagonal chatoyancy may be seen. It is due to fibrous inclusions contained in each of the six spokes that radiate outward from the core.
Natural Diamonds Face Competition From Synthetic
Times News Network writes:
While the gems and jewellery industry is preparing itself to take on the Chinese dragon, the problem of synthetic diamonds making steady in-roads lurks beneath the shiny surface of the industry.
“India is a price sensitive market and synthetic diamonds could give competition to natural diamonds over the next decade,” said Ronald Lorie, CEO of International Gemological Institute (IGI).
Synthetic or cultured diamonds are laboratory-created diamonds that have the same chemical, optical and physical characteristics as mined diamonds. The two are literally indistinguishable to the naked eyes.
The IGI’s Mumbai Gemological laboratory receive close to three to four synthetic diamonds of yellowish orange colour every week, which are easily identifiable. But it is not the case with white synthetic diamonds, which look very similar to original diamonds, admits Mr Lorie.
Even the recently published KPMG report on the industry speaks broadly about the emergence of synthetic diamonds as a commercially viable alternative posing a new challenge for the world’s diamond industry. There is a dual threat to the natural diamond industry — threat of substitution and deception impacting consumer confidence and the threat of changing consumer preference, said the report.
The KPMG has estimated the current value of synthetic at wholesale to be close to $50 million and expects the market to grow at a CAGR of 45% over the next 10 years. Giving the current situation the sale of synthetic diamonds jewellery is likely to cross $2 billion by 2015 at wholesale against the sale of natural diamond jewellery sales of $6 billion at the retail level.
With the view to inform and protect the consumers and the industry, the IGI has started grading the synthetic diamonds from January 1, 2007. IGI has been laser inscribing synthetic diamonds it grades this way with the words ‘laboratory-grown,’ said Mr Lorie.
Chandrakant Sanghvi, regional chairman of GJEPC said: “There is no threat to the industry at this moment.” But synthetic diamonds could replace the natural diamonds in jewellery due to its cheap value.”
Chuni Gajera owner of Laxmi Diamond said: “Synthetic diamond can give a stiff competition to natural diamonds. But synthetics are not being sold as real. Synthetics could gain momentum in the sale of jewellery.
More info @ http://economictimes.indiatimes.com/Markets/Commodities/Natural_diamonds_face_competition_from_synthetics_/articleshow/1144422.cms
While the gems and jewellery industry is preparing itself to take on the Chinese dragon, the problem of synthetic diamonds making steady in-roads lurks beneath the shiny surface of the industry.
“India is a price sensitive market and synthetic diamonds could give competition to natural diamonds over the next decade,” said Ronald Lorie, CEO of International Gemological Institute (IGI).
Synthetic or cultured diamonds are laboratory-created diamonds that have the same chemical, optical and physical characteristics as mined diamonds. The two are literally indistinguishable to the naked eyes.
The IGI’s Mumbai Gemological laboratory receive close to three to four synthetic diamonds of yellowish orange colour every week, which are easily identifiable. But it is not the case with white synthetic diamonds, which look very similar to original diamonds, admits Mr Lorie.
Even the recently published KPMG report on the industry speaks broadly about the emergence of synthetic diamonds as a commercially viable alternative posing a new challenge for the world’s diamond industry. There is a dual threat to the natural diamond industry — threat of substitution and deception impacting consumer confidence and the threat of changing consumer preference, said the report.
The KPMG has estimated the current value of synthetic at wholesale to be close to $50 million and expects the market to grow at a CAGR of 45% over the next 10 years. Giving the current situation the sale of synthetic diamonds jewellery is likely to cross $2 billion by 2015 at wholesale against the sale of natural diamond jewellery sales of $6 billion at the retail level.
With the view to inform and protect the consumers and the industry, the IGI has started grading the synthetic diamonds from January 1, 2007. IGI has been laser inscribing synthetic diamonds it grades this way with the words ‘laboratory-grown,’ said Mr Lorie.
Chandrakant Sanghvi, regional chairman of GJEPC said: “There is no threat to the industry at this moment.” But synthetic diamonds could replace the natural diamonds in jewellery due to its cheap value.”
Chuni Gajera owner of Laxmi Diamond said: “Synthetic diamond can give a stiff competition to natural diamonds. But synthetics are not being sold as real. Synthetics could gain momentum in the sale of jewellery.
More info @ http://economictimes.indiatimes.com/Markets/Commodities/Natural_diamonds_face_competition_from_synthetics_/articleshow/1144422.cms
How To Separate Frequently Encountered Red Stones
- Visual observation: (10x lens) Look for color, luster, cut, doublet/triplet junctions, if any.
- Determine optic character: Single refractive (SR) / Double refractive (DR) / Anomalous Double
refractive (ADR) / Aggregate (AGG).
- Spectrum: Many red stones may have diagnostic spectrum.
- Microscope: Inclusions may be diagnostic, but look for inclusions that differentiate natural and
synthetic, doublet / triplet.
- Dichroscope: Different cutting orientations of natural and synthetic corundum may be revealed
by dichroscope.
- Fluorescence: Look under shortwave and longwave for diagnostic colors.
- Immersion cell: Use immersion cell and high refractive index liquid to separate doublets/triplets.
- Refractometer: Confirm spectroscope reading with refractometer.
The red stones, which may resemble one another in appearance and values, are:
Red Beryl
- Hardness: 7.5
- Specific gravity: 2.70 (average)
- Refractive index: 1.57 – 1.58
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.006
- Other points: Inclusions, color.
Tourmaline
- Hardness: 7
- Specific gravity: 3.03
- Refractive index: 1.62 – 1.64
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.018
- Other points: Inclusions, color, pleochroism. There are many treated tourmalines in the gem market. Many
gem quality tourmalines are relatively clean. Analytical techniques may be required to detect treatments.
Topaz
- Hardness: 8
- Specific gravity: 3.53
- Refractive index: 1.63 – 1.64
- Optic sign: Biaxial positive
- Birefringence: DR; 0.008
- Other points: Inclusions, color (pink stones may be confused for pink sapphires). There are many treated
topaz in the market. Most gem quality stones are relatively clean. Analytical techniques may be required
to detect treatments.
Spinel
- Hardness: 8
- Specific gravity: 3.60
- Refractive index: 1.718
- Optic sign: SR
- Birefringence: -
- Other points: Inclusions, color, spectrum.
Garnet (pyrope)
- Hardness: 7.5
- Specific gravity: 3.78 (average)
- Refractive index: 1.75 (average)
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Inclusions, color (may be confused for Thai ruby / synthetic ruby), spectrum.
Garnet (almandine)
- Hardness: 7.5
- Specific gravity: 4.10 (average)
- Refractive index: 1.78 (average)
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Inclusions, color (may be confused for Thai ruby / synthetic ruby), spectrum.
Ruby
- Hardness: 9
- Specific gravity: 4 (average)
- Refractive index: 1.76 – 1.77 (average)
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.008
- Other points: Inclusions, color, spectrum (use microscope to separate natural vs synthetic).
Synthetic Ruby
- Hardness: 9
- Specific gravity: 4 (average)
- Refractive index: 1.76 – 1.77 (average)
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.008
- Other points: Inclusions, color, spectrum (use microscope to differentiate flux and hydrothermal).
Synthetic red cubic zirconia
- Hardness: 8.5
- Specific gravity: 5.65 +
- Refractive index: 2.15 +
- Optic sign: SR
- Birefringence: -
- Other points: negative refractive index, luster, color, orange flash on the pavilion, dispersion.
Red Zircon
- Hardness: 7.5
- Specific gravity: 4.69
- Refractive index: 1.93 – 1.99
- Optic sign: Uniaxial positive
- Birefringence: DR; 0.059
- Other points: Inclusions, color, spectrum, doubling of the back facets, dispersion, luster, negative refractive
index reading.
Red Diamond
- Hardness: 10
- Specific gravity: 3.52
- Refractive index: 2.42
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Rare, negative refractive index reading, inclusions, luster, spectrum, dispersion. There are
many treated diamonds in the market. Most treated diamonds are relatively clean. Analytical techniques
may be required to detect treatments.
Synthetic red diamond
- Hardness: 10
- Specific gravity: 3.52
- Refractive index: 2.42
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Negative refractive index reading, color, inclusions, luster, spectrum, fluorescence. Synthetic
diamonds are produced by the high pressure high temperature method. Gem quality stones are relatively
clean. Analytical techniques may be required to identify the stones.
Glass
- Hardness: 5.5
- Specific gravity: 3.70
- Refractive index: 1.60 – 1.66
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Soft, inclusions (gas bubbles), color.
Assembled Stones
Doublets / Triplets
Corundum (natural crown / synthetic base)
Other points: Immersion (Look for differences in color and luster between the sections).
Garnet topped doublet (glass)
- Refractive index: 1.76 +
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Look for differences in color and luster between the sections, gas bubbles).
Synthetic spinel soude (spinel / spinel)
- Refractive index: 1.728
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Look for differences in color and luster between the sections, gas bubbles).
- Determine optic character: Single refractive (SR) / Double refractive (DR) / Anomalous Double
refractive (ADR) / Aggregate (AGG).
- Spectrum: Many red stones may have diagnostic spectrum.
- Microscope: Inclusions may be diagnostic, but look for inclusions that differentiate natural and
synthetic, doublet / triplet.
- Dichroscope: Different cutting orientations of natural and synthetic corundum may be revealed
by dichroscope.
- Fluorescence: Look under shortwave and longwave for diagnostic colors.
- Immersion cell: Use immersion cell and high refractive index liquid to separate doublets/triplets.
- Refractometer: Confirm spectroscope reading with refractometer.
The red stones, which may resemble one another in appearance and values, are:
Red Beryl
- Hardness: 7.5
- Specific gravity: 2.70 (average)
- Refractive index: 1.57 – 1.58
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.006
- Other points: Inclusions, color.
Tourmaline
- Hardness: 7
- Specific gravity: 3.03
- Refractive index: 1.62 – 1.64
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.018
- Other points: Inclusions, color, pleochroism. There are many treated tourmalines in the gem market. Many
gem quality tourmalines are relatively clean. Analytical techniques may be required to detect treatments.
Topaz
- Hardness: 8
- Specific gravity: 3.53
- Refractive index: 1.63 – 1.64
- Optic sign: Biaxial positive
- Birefringence: DR; 0.008
- Other points: Inclusions, color (pink stones may be confused for pink sapphires). There are many treated
topaz in the market. Most gem quality stones are relatively clean. Analytical techniques may be required
to detect treatments.
Spinel
- Hardness: 8
- Specific gravity: 3.60
- Refractive index: 1.718
- Optic sign: SR
- Birefringence: -
- Other points: Inclusions, color, spectrum.
Garnet (pyrope)
- Hardness: 7.5
- Specific gravity: 3.78 (average)
- Refractive index: 1.75 (average)
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Inclusions, color (may be confused for Thai ruby / synthetic ruby), spectrum.
Garnet (almandine)
- Hardness: 7.5
- Specific gravity: 4.10 (average)
- Refractive index: 1.78 (average)
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Inclusions, color (may be confused for Thai ruby / synthetic ruby), spectrum.
Ruby
- Hardness: 9
- Specific gravity: 4 (average)
- Refractive index: 1.76 – 1.77 (average)
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.008
- Other points: Inclusions, color, spectrum (use microscope to separate natural vs synthetic).
Synthetic Ruby
- Hardness: 9
- Specific gravity: 4 (average)
- Refractive index: 1.76 – 1.77 (average)
- Optic sign: Uniaxial negative
- Birefringence: DR; 0.008
- Other points: Inclusions, color, spectrum (use microscope to differentiate flux and hydrothermal).
Synthetic red cubic zirconia
- Hardness: 8.5
- Specific gravity: 5.65 +
- Refractive index: 2.15 +
- Optic sign: SR
- Birefringence: -
- Other points: negative refractive index, luster, color, orange flash on the pavilion, dispersion.
Red Zircon
- Hardness: 7.5
- Specific gravity: 4.69
- Refractive index: 1.93 – 1.99
- Optic sign: Uniaxial positive
- Birefringence: DR; 0.059
- Other points: Inclusions, color, spectrum, doubling of the back facets, dispersion, luster, negative refractive
index reading.
Red Diamond
- Hardness: 10
- Specific gravity: 3.52
- Refractive index: 2.42
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Rare, negative refractive index reading, inclusions, luster, spectrum, dispersion. There are
many treated diamonds in the market. Most treated diamonds are relatively clean. Analytical techniques
may be required to detect treatments.
Synthetic red diamond
- Hardness: 10
- Specific gravity: 3.52
- Refractive index: 2.42
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Negative refractive index reading, color, inclusions, luster, spectrum, fluorescence. Synthetic
diamonds are produced by the high pressure high temperature method. Gem quality stones are relatively
clean. Analytical techniques may be required to identify the stones.
Glass
- Hardness: 5.5
- Specific gravity: 3.70
- Refractive index: 1.60 – 1.66
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Soft, inclusions (gas bubbles), color.
Assembled Stones
Doublets / Triplets
Corundum (natural crown / synthetic base)
Other points: Immersion (Look for differences in color and luster between the sections).
Garnet topped doublet (glass)
- Refractive index: 1.76 +
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Look for differences in color and luster between the sections, gas bubbles).
Synthetic spinel soude (spinel / spinel)
- Refractive index: 1.728
- Optic sign: SR/ADR
- Birefringence: -
- Other points: Look for differences in color and luster between the sections, gas bubbles).
Monday, January 15, 2007
Overweighing What Can Be Counted
Charles T Munger, Vice-Chairman of Berkshire Hathaway Corporation writes:
The late, great, Thomas Hunt Morgan, who was one of the greatest biologist who ever lived, when he got to Caltech, had a very interesting, extreme way of avoiding some mistakes from overcounting what could be measured, and undercounting what couldn't. At that time there were no computers and the computer substitute then available to science and engineering was the Frieden calculator, and Caltech was full of Frieden calculators. And Thomas Hunt Morgan banned the Frieden calculator from the biology department. And when they said, "What the hell are you doing, Mr Morgan?" He said, "Well, I am like a guy who is prospecting for gold along the banks of the Sacramento River in 1849. With a little intelligence, I can reach down and pick up big nuggets of gold. And as long as I can do that, I'm not going to let any people in my department waste scarce resources in placer mining." And that's the way Thomas Hunt Morgan got through life.
I have adopted the same technique. I haven't had to do any placer mining yet. And it begins to look like I'm going to get all the way through, as I had always hoped, without doing any of that damned placer mining. Of course if I were a physician, particularly an academic physician, I'd have to do the statistics, do the placer mining. But it's amazing what you can do in life without placer mining if you've got a few good mental tricks and just keep ragging the problems the way Thomas Hunt Morgan did.
The late, great, Thomas Hunt Morgan, who was one of the greatest biologist who ever lived, when he got to Caltech, had a very interesting, extreme way of avoiding some mistakes from overcounting what could be measured, and undercounting what couldn't. At that time there were no computers and the computer substitute then available to science and engineering was the Frieden calculator, and Caltech was full of Frieden calculators. And Thomas Hunt Morgan banned the Frieden calculator from the biology department. And when they said, "What the hell are you doing, Mr Morgan?" He said, "Well, I am like a guy who is prospecting for gold along the banks of the Sacramento River in 1849. With a little intelligence, I can reach down and pick up big nuggets of gold. And as long as I can do that, I'm not going to let any people in my department waste scarce resources in placer mining." And that's the way Thomas Hunt Morgan got through life.
I have adopted the same technique. I haven't had to do any placer mining yet. And it begins to look like I'm going to get all the way through, as I had always hoped, without doing any of that damned placer mining. Of course if I were a physician, particularly an academic physician, I'd have to do the statistics, do the placer mining. But it's amazing what you can do in life without placer mining if you've got a few good mental tricks and just keep ragging the problems the way Thomas Hunt Morgan did.
Diamond Cut: Escada Cut
The Escada cut is the creation of Pluczenik Group, the Antwerp-based master cutters and sightholders. The cut is trade marked and patented to the Pluczenik Group.
The Escada diamond jewelry concept is the result of innovative input from Italian luxury jewelry producer Crova and creative marketing by the De Beers Diamond Trading Company. The cut symbolizes the ever renewing cycle of 12 months of the year.
The cut is a 12-sided dodecagonal cut with unique geometry of facets. The 97-facet stones are difficult to cut. It requires the most advanced cutting techniques and technology.
All stones above 0.20carats will be identified with a laser inscription on the girdle and will be lab certified. The Escada logo will also appear on the shank of each ring.
The Escada Diamond Jewelry Collection is sold through Escada’s integrated distribution network at the company’s 365 stores in more than 50 countries and at high-end department stores.
The Escada diamond jewelry concept is the result of innovative input from Italian luxury jewelry producer Crova and creative marketing by the De Beers Diamond Trading Company. The cut symbolizes the ever renewing cycle of 12 months of the year.
The cut is a 12-sided dodecagonal cut with unique geometry of facets. The 97-facet stones are difficult to cut. It requires the most advanced cutting techniques and technology.
All stones above 0.20carats will be identified with a laser inscription on the girdle and will be lab certified. The Escada logo will also appear on the shank of each ring.
The Escada Diamond Jewelry Collection is sold through Escada’s integrated distribution network at the company’s 365 stores in more than 50 countries and at high-end department stores.
Cleaning Cubic Zirconia
Victor Epand writes:
The basic rule of jewelry care is to apply all lotions, make-up, hair spray, etc. first, then put on the jewelry. Pearls are especially susceptive to the solvents in hair sprays. In the reality of the jewelry business, I see people who refuse to remove rings and those who do so only once in a while. When we clean a customer's jewelry and inspect for wear and loose or missing stones, the jewelry most often needing repair is a ring that is "never" taken off the finger and cleaned by the owner.
Persistent dirt gets between the metal settings and the stones causing abrasive wear and eventually perhaps a loose stone. Everyday wear on the outside of stone settings may lead to lost stones, too. A regular home cleaning and good look at the jewelry will prevent most stone loses, allowing for repair or tightening before it is too late. It is not common to see really clean jewelry come into the shop. When we do, that jewelry is generally in much better condition than the dirty items.
Hand lotions and soap film are some of the more difficult materials to remove. With CZ stones, a clean stone is vital to keep the "sparkling diamond" look. Just a little lotion on the bottom of the stone will take away much of the visual life of the stone. Fortunately, CZ's are fairly hard and tough. Cleaning may be more aggressive than with stones like opal or pearls, for example.
Start by taking the ring off the finger long enough to clean it! Using a soft tooth brush and a warm to hot solution of a dishwashing detergent like Joy, brush as well as possible to remove the scum and lotion. Rinse well in warm water. Pat dry and take a look. If more cleaning is needed, soak the ring in hot tap water with about 1/3 detergent to 2/3 hot water.(The mix is not critical.) Then brush again.
The brush and even the end of a toothpick will not damage the stone. Do not use any abrasive cleansers. Most will not damage a CZ but will take the shine off the metal and might scratch some softer kinds of gemstones. Do not use toothpaste or similar stuff. Short of buying a small home sized ultrasonic cleaner, the detergent approach is one of the best for home use.
With CZ a little sudsy ammonia may be added and will greatly improve the cleaning speed and effectiveness. Don't use any ammonia cleaners with silver, turquoise or pearls. Ammonia will cause spots on sterling. Use enough ammonia to liven up the faint hearted and do have a window open and some air moving.
With regular cleaning, you "get to know" the jewelry and can spot worn metal and loose stones before a loss happens.
When you cannot get the dirt off, let the jewelry store clean and inspect the jewelry. Strong detergents in heated ultrasonic cleaners followed with high pressure steam cleaning will remove most all dirt. Soap scum takes a little longer but comes off ok.
CZ is hard enough to cut glass. Most faceted gemstones are hard enough to cut glass. However, dust in the air contains a lot of silica (think sand). Hand lotions will leave a film on jewelry for dust to stick to. Over time, this rock dust in the air will abrade metal settings and some softer gemstones. Keep the lotion off the jewelry if at all possible. Not only does lotion free jewelry sparkle and look better every day, it will wear longer, too.
Victor Epand is the owner of http://www.jewelrygift.biz
More info @ http://EzineArticles.com/?expert=Victor_Epandhttp://ezinearticles.com/?Cleaning-Cubic-Zirconia&id=411891
The basic rule of jewelry care is to apply all lotions, make-up, hair spray, etc. first, then put on the jewelry. Pearls are especially susceptive to the solvents in hair sprays. In the reality of the jewelry business, I see people who refuse to remove rings and those who do so only once in a while. When we clean a customer's jewelry and inspect for wear and loose or missing stones, the jewelry most often needing repair is a ring that is "never" taken off the finger and cleaned by the owner.
Persistent dirt gets between the metal settings and the stones causing abrasive wear and eventually perhaps a loose stone. Everyday wear on the outside of stone settings may lead to lost stones, too. A regular home cleaning and good look at the jewelry will prevent most stone loses, allowing for repair or tightening before it is too late. It is not common to see really clean jewelry come into the shop. When we do, that jewelry is generally in much better condition than the dirty items.
Hand lotions and soap film are some of the more difficult materials to remove. With CZ stones, a clean stone is vital to keep the "sparkling diamond" look. Just a little lotion on the bottom of the stone will take away much of the visual life of the stone. Fortunately, CZ's are fairly hard and tough. Cleaning may be more aggressive than with stones like opal or pearls, for example.
Start by taking the ring off the finger long enough to clean it! Using a soft tooth brush and a warm to hot solution of a dishwashing detergent like Joy, brush as well as possible to remove the scum and lotion. Rinse well in warm water. Pat dry and take a look. If more cleaning is needed, soak the ring in hot tap water with about 1/3 detergent to 2/3 hot water.(The mix is not critical.) Then brush again.
The brush and even the end of a toothpick will not damage the stone. Do not use any abrasive cleansers. Most will not damage a CZ but will take the shine off the metal and might scratch some softer kinds of gemstones. Do not use toothpaste or similar stuff. Short of buying a small home sized ultrasonic cleaner, the detergent approach is one of the best for home use.
With CZ a little sudsy ammonia may be added and will greatly improve the cleaning speed and effectiveness. Don't use any ammonia cleaners with silver, turquoise or pearls. Ammonia will cause spots on sterling. Use enough ammonia to liven up the faint hearted and do have a window open and some air moving.
With regular cleaning, you "get to know" the jewelry and can spot worn metal and loose stones before a loss happens.
When you cannot get the dirt off, let the jewelry store clean and inspect the jewelry. Strong detergents in heated ultrasonic cleaners followed with high pressure steam cleaning will remove most all dirt. Soap scum takes a little longer but comes off ok.
CZ is hard enough to cut glass. Most faceted gemstones are hard enough to cut glass. However, dust in the air contains a lot of silica (think sand). Hand lotions will leave a film on jewelry for dust to stick to. Over time, this rock dust in the air will abrade metal settings and some softer gemstones. Keep the lotion off the jewelry if at all possible. Not only does lotion free jewelry sparkle and look better every day, it will wear longer, too.
Victor Epand is the owner of http://www.jewelrygift.biz
More info @ http://EzineArticles.com/?expert=Victor_Epandhttp://ezinearticles.com/?Cleaning-Cubic-Zirconia&id=411891
Diamond Cut: Phoenix Cut
Phoenix cut is produced at Smolensk Production Corporation Kristall, which specializes in high-quality goods known worldwide as the ‘Russian make’. The design is based on emerald and princess cuts.
The Phoenix has 85 facets: 39 in the crown, 38 in the pavilion, and 8 facets composing the girdle. The majority of Phoenix cut diamond range from 0.50 to 2 carats.
The Phoenix cut was designed in 1993. The Phoenix cut concept is associated with the legendary Phoenix bird that revived itself from the ashes of a fatal fire.
Phoenix cut diamonds are sold through Smolensk Kristall's offices in Antwerp and Hong Kong.
The Phoenix has 85 facets: 39 in the crown, 38 in the pavilion, and 8 facets composing the girdle. The majority of Phoenix cut diamond range from 0.50 to 2 carats.
The Phoenix cut was designed in 1993. The Phoenix cut concept is associated with the legendary Phoenix bird that revived itself from the ashes of a fatal fire.
Phoenix cut diamonds are sold through Smolensk Kristall's offices in Antwerp and Hong Kong.
How To Make Money
Warren Edward Buffett, CEO, Berkshire Hathaway writes:
'John Maynard Keynes, whose brilliance as a practicing investor matched his brilliance in thought, wrote a letter to a business associate, F. C. Scott, on August 15, 1934 that says it all: 'As time goes on, I get more and more convinced that the right method in investment is to put fairly large sums into enterprises which one thinks one knows something about and in the management of which one thoroughly believes. It is a mistake to think that one limits one's risk by spreading too much between enterprises about which one knows little and has no reason for special confidence… One's knowledge and experience are definitely limited and there are seldom more than two or three enterprises at any given time in which I personally feel myself entitled to put full confidence.'
'John Maynard Keynes, whose brilliance as a practicing investor matched his brilliance in thought, wrote a letter to a business associate, F. C. Scott, on August 15, 1934 that says it all: 'As time goes on, I get more and more convinced that the right method in investment is to put fairly large sums into enterprises which one thinks one knows something about and in the management of which one thoroughly believes. It is a mistake to think that one limits one's risk by spreading too much between enterprises about which one knows little and has no reason for special confidence… One's knowledge and experience are definitely limited and there are seldom more than two or three enterprises at any given time in which I personally feel myself entitled to put full confidence.'
The Difference Between Real and Fake Jewelry
Victor Epand writes:
The law requires metal to be marked by the maker and the metal quality. For sterling, the mark will be either the numbers 925 (meaning 92.5 % silver, which is sterling) or a "sterling" stamp with the words. Near the clasp should have the mark, it would be at the end of the chain if anything. Sometimes the mark is on a little flat looking ring at the end of the chain, so check around.
Sterling silver will tarnish and on some people it tarnishes quickly due to body chemistry, but on others it may never tarnish. To keep tarnish from happening, sterling is very often plated with another metal to protect the sterling and keep the tarnish from happening. The plating will be a metal called "rhodium" which is very bright or another metal recently used on silver that looks more the color of silver. However, the chain can be sterling and still have the plate on the outside to prevent tarnish.
Other than that, the only real way to tell if something is sterling silver is to test it. For example, like an acid test done by a jeweler. Generally a test will cost some money, not a lot, but maybe not worth it, depending on what you paid for the chain. On a large heavy chain, the test might be worth it, but that's all up to you.
I suggest thinking about where you got the chain from and whether or not you got it from an established business. An established business would serve little purpose in selling anything fake for sterling silver. Always look for both a sterling marks and a stamp or symbol for the manufacture as I said before. Both of those marks should be there.
Here's some information on how to tell if the gold on your bracelet is really gold. The chlorine in bleach is dangerous to gold jewelry, so it's best not to test gold in bleach, or else you'll ruin your jewelry. Stress points like where the metal has been hammered, bent over stones in prongs, formed by chain making machines and the like are the most affected by chlorine. Soldered areas are sometimes affected by chlorine. White gold is most easily damaged but apparently this happens with yellow gold also at stress points in the metal.
Chlorine will cause a darkening on gold, but on yellow gold it looks almost like a very pale gray color. White gold reacts the same way but sometimes goes darker. This is the chlorine reacting to the metals in karat gold. All jewelry metal of 18k, 14k and 10k has other metals in the recipe when the metal is made. Pure gold is mixed with mostly silver and copper (with nickel or palladium with white gold) to make metal strong enough for jewelry.
The karat mark shows how much pure gold is in the mix. For instance, pure gold is called 24k. Now, 10k will have 10 parts pure gold and 14 parts of the other metals, all adding up to 24 part. 18k gold will be 18 parts pure gold and 6 parts other metals, all adding up to 24 parts. That is how it goes with karats.
Yellow gold is not as dangerously affected by chlorine in bleach and a good buffing should make it ok, that is, if it is really gold. The best way to see if it is real karat gold is to have it tested. That means an acid test or a test using one of the newer electronic gold testers some jewelers use. That is what I would recommend.
Victor Epand is the owner of http://www.jewelrygift.biz
More info @ http://ezinearticles.com/?The-Difference-Between-Real-and-Fake-Jewelry&id=411792
http://EzineArticles.com/?expert=Victor_Epand
The law requires metal to be marked by the maker and the metal quality. For sterling, the mark will be either the numbers 925 (meaning 92.5 % silver, which is sterling) or a "sterling" stamp with the words. Near the clasp should have the mark, it would be at the end of the chain if anything. Sometimes the mark is on a little flat looking ring at the end of the chain, so check around.
Sterling silver will tarnish and on some people it tarnishes quickly due to body chemistry, but on others it may never tarnish. To keep tarnish from happening, sterling is very often plated with another metal to protect the sterling and keep the tarnish from happening. The plating will be a metal called "rhodium" which is very bright or another metal recently used on silver that looks more the color of silver. However, the chain can be sterling and still have the plate on the outside to prevent tarnish.
Other than that, the only real way to tell if something is sterling silver is to test it. For example, like an acid test done by a jeweler. Generally a test will cost some money, not a lot, but maybe not worth it, depending on what you paid for the chain. On a large heavy chain, the test might be worth it, but that's all up to you.
I suggest thinking about where you got the chain from and whether or not you got it from an established business. An established business would serve little purpose in selling anything fake for sterling silver. Always look for both a sterling marks and a stamp or symbol for the manufacture as I said before. Both of those marks should be there.
Here's some information on how to tell if the gold on your bracelet is really gold. The chlorine in bleach is dangerous to gold jewelry, so it's best not to test gold in bleach, or else you'll ruin your jewelry. Stress points like where the metal has been hammered, bent over stones in prongs, formed by chain making machines and the like are the most affected by chlorine. Soldered areas are sometimes affected by chlorine. White gold is most easily damaged but apparently this happens with yellow gold also at stress points in the metal.
Chlorine will cause a darkening on gold, but on yellow gold it looks almost like a very pale gray color. White gold reacts the same way but sometimes goes darker. This is the chlorine reacting to the metals in karat gold. All jewelry metal of 18k, 14k and 10k has other metals in the recipe when the metal is made. Pure gold is mixed with mostly silver and copper (with nickel or palladium with white gold) to make metal strong enough for jewelry.
The karat mark shows how much pure gold is in the mix. For instance, pure gold is called 24k. Now, 10k will have 10 parts pure gold and 14 parts of the other metals, all adding up to 24 part. 18k gold will be 18 parts pure gold and 6 parts other metals, all adding up to 24 parts. That is how it goes with karats.
Yellow gold is not as dangerously affected by chlorine in bleach and a good buffing should make it ok, that is, if it is really gold. The best way to see if it is real karat gold is to have it tested. That means an acid test or a test using one of the newer electronic gold testers some jewelers use. That is what I would recommend.
Victor Epand is the owner of http://www.jewelrygift.biz
More info @ http://ezinearticles.com/?The-Difference-Between-Real-and-Fake-Jewelry&id=411792
http://EzineArticles.com/?expert=Victor_Epand
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