Today the 4 different types of simulants for Paraiba tourmaline are still encountered in all shapes and sizes.
(via ICA Early Warning Flash, No.47, September 20, 1991) Deutsche Stiftung Edelsteinforschung writes:
Details
In the last weeks some remarkable simulants for blue and greenish blue Paraiba tourmalines have been observed in Idar Oberstein. In lots of cut stones 4 different types of simulants have been found.
- Blue to greenish blue apatite
- Blue irradiated topaz (unheated)
- Beryl-beryl-triplets with a bright blue cement
- Tourmaline glass doublets
Blue and greenish blue apatite has also been found in lots of rough Paraiba tourmalines.
Identification
1. Apatite possesses refractive indices in the same range as tourmaline but the birefringence is distinctly lower. Furthermore, the absorption spectra are quite different; blue and greenish blue apatite shows absorption lines in the red and yellow, which are caused by certain color centers, while Paraiba tourmalines owe their color to copper and manganese, which cause broad absorption bands in the red and green spectral range.
2. Blue irradiated topaz has lower refractive indices than tourmaline and additionally a lower
birefringence, while the density is higher. The artificial coloration by irradiation has been tested by thermoluminescence measurements.
3. The beryl-beryl-triplets are detectable by the lower refractive indices and birefringence compared to tourmaline. The cementing layer can be easily observed by microscopical studies.
4. The tourmaline-glass-doublets can cause more difficulties because the upper part consists of tourmaline. But microscopical observations attest the composite stone. Routine tests revealed doubling of the back facets of tourmaline and single refraction of glass.
Conclusion
Be careful with lots, and investigate each stone of every lot individually even if or especially when the color is similar or nearly the same.
Friday, March 23, 2007
Be On The Lookout For Fake Amber
(via Wahroongai News, Volume 32, Number 3, March 1998) Grahame Brown writes:
This warning follows the recently held North Brisbane Lapidary Show at which one dealer was found to be selling materials clearly marked as amber—yet these materials were not amber. One group of the ambers for sale were manufactured from the amber imitation polyberne; and other pale yellowish ambers were obviously recent copal resin (some of which was attractively included by insect inclusions).
To assist members and students not to be taken in by this scam, the following information is supplied on these two amber imitations and their identification.
Copal Resin
Copal resin is a diaphanous brittle colorless, yellow to brownish recent plant resin that may have an age of up to several tens of thousands of years. Commercial copal resins are often given names such as Kauri gum (a misnomer), Manila, Congo or Colombian copal.
Kauri gum and manila are respectively derived from sap from the gymnosperms Agathis australis from the North Island of New Zealand and Agathis albis from the Philippines and the Indonesian archipelago. There are two major African sources of copal resin which also may be termed congo or Zanzibar resin. East African copal, which comes from Tanzania and island of Zanzibar, is derived from sap exuded from damaged trunks and branches of the leguminous (fruit-bearing) angiosperm (flowering plant) Hymenaea verrucosa; while West African copal from the Congo Republic is derived from the sap of the leguminous angiosperm Copiafera demusi. Most Colombian copal comes from ploughed fields in the Departments of Santander, Boyaca, and Bolivar—specifically near the cities and villages of Bucaramanga, Giron, Bonda, Medellin, Penablanca, Mariquita, and Valle du Jesus. Some Colombian copal has been given the tongue-twisting name of bucarimangite. Age dating of specimens of Colombian copal has yielded ages that ranged from 10 to 500 years. The source resin of Colombian copal is undoubtedly three resin producing trees that are still growing in Colombia—the Hymenaea courbaril, the H. oblongifolia, and the H. parvifolia. In these trees the exuded resin accumulates between the bark and wood, and also under the roots of the tree. Common inclusions in this very recent resin include stingless bees, millipedes, centipedes, ants, moths, beetles, cockroaches, silverfish, and termites.
Precisely how long copal resin takes to convert to amber is unknown. However, this (hardening) time is influenced by such conditions as temperature, pressure, moisture, and perhaps the presence or absence of oxygen. Poinar (1994) suggested that 2-4 million years of burial might be required to convert copal resin into amber.
Copal resin and/or kauri gum are excellent amber look-alikes so with the exception copal’s:
Slightly lower hardness (2 on Mohs scale).
Slightly lower specific gravity (varying from 1.3 to 1.09 with age).
Increased solubility in volatile hydrocarbons.
Increased volatility, with a ‘pine’-like odor being emitted when kauri and/or copal is firmly rubbed in the heel of the hand.
Increased shallow surface crazing, restricted to the outer 2mm of the resin, due to continuing evaporation of volatiles.
………these effective amber imitations have an appearance, gemological properties, sectility (chips on peeling), and pattern of inclusions virtually identical to those of amber.
Practically, the increased solubility of kauri gum/copal resin in volatile organic solvents (a potentially destructive test) may be used to effectively discriminate them from amber, as
1. Surfaces of copal resin become sticky to an applied finger following the judicious application of a drop of volatile organic solvent (e.g. ether, chloroform, acetone, or alcohol) to an inconspicuous area of the suspect resin. This is a very useful test that can be applied before you purchase specimens of ? amber; and,
2. A yellow stain will be deposited on the surface of an alcohol-moistened white cloth or tissue, when an inconspicuous surface of kauri and/or copal is wiped briskly with a moistened cloth or tissue.
Polyberne
Polyberne, a man-made composite imitation of amber consists of fragments of amber embedded in brownish polyester casting resin. Polyberne is a distinctly Polish product that displays evidence of:
- Molding.
- Entrapment of air bubbles between the external surface of the imitation and the mold into which the polyester resin was poured.
- Evidence of two components. That is fragments of amber embedded in a resin of different refractive index.
Hand lens examination, looking for evidence of embedding and molding, and perhaps a test for sectility, are all that is required to positively identify the polyberne imitation of amber.
So beware, these materials are in the marketplace. Do not be caught for want of applying a few simple observations and tests.
This warning follows the recently held North Brisbane Lapidary Show at which one dealer was found to be selling materials clearly marked as amber—yet these materials were not amber. One group of the ambers for sale were manufactured from the amber imitation polyberne; and other pale yellowish ambers were obviously recent copal resin (some of which was attractively included by insect inclusions).
To assist members and students not to be taken in by this scam, the following information is supplied on these two amber imitations and their identification.
Copal Resin
Copal resin is a diaphanous brittle colorless, yellow to brownish recent plant resin that may have an age of up to several tens of thousands of years. Commercial copal resins are often given names such as Kauri gum (a misnomer), Manila, Congo or Colombian copal.
Kauri gum and manila are respectively derived from sap from the gymnosperms Agathis australis from the North Island of New Zealand and Agathis albis from the Philippines and the Indonesian archipelago. There are two major African sources of copal resin which also may be termed congo or Zanzibar resin. East African copal, which comes from Tanzania and island of Zanzibar, is derived from sap exuded from damaged trunks and branches of the leguminous (fruit-bearing) angiosperm (flowering plant) Hymenaea verrucosa; while West African copal from the Congo Republic is derived from the sap of the leguminous angiosperm Copiafera demusi. Most Colombian copal comes from ploughed fields in the Departments of Santander, Boyaca, and Bolivar—specifically near the cities and villages of Bucaramanga, Giron, Bonda, Medellin, Penablanca, Mariquita, and Valle du Jesus. Some Colombian copal has been given the tongue-twisting name of bucarimangite. Age dating of specimens of Colombian copal has yielded ages that ranged from 10 to 500 years. The source resin of Colombian copal is undoubtedly three resin producing trees that are still growing in Colombia—the Hymenaea courbaril, the H. oblongifolia, and the H. parvifolia. In these trees the exuded resin accumulates between the bark and wood, and also under the roots of the tree. Common inclusions in this very recent resin include stingless bees, millipedes, centipedes, ants, moths, beetles, cockroaches, silverfish, and termites.
Precisely how long copal resin takes to convert to amber is unknown. However, this (hardening) time is influenced by such conditions as temperature, pressure, moisture, and perhaps the presence or absence of oxygen. Poinar (1994) suggested that 2-4 million years of burial might be required to convert copal resin into amber.
Copal resin and/or kauri gum are excellent amber look-alikes so with the exception copal’s:
Slightly lower hardness (2 on Mohs scale).
Slightly lower specific gravity (varying from 1.3 to 1.09 with age).
Increased solubility in volatile hydrocarbons.
Increased volatility, with a ‘pine’-like odor being emitted when kauri and/or copal is firmly rubbed in the heel of the hand.
Increased shallow surface crazing, restricted to the outer 2mm of the resin, due to continuing evaporation of volatiles.
………these effective amber imitations have an appearance, gemological properties, sectility (chips on peeling), and pattern of inclusions virtually identical to those of amber.
Practically, the increased solubility of kauri gum/copal resin in volatile organic solvents (a potentially destructive test) may be used to effectively discriminate them from amber, as
1. Surfaces of copal resin become sticky to an applied finger following the judicious application of a drop of volatile organic solvent (e.g. ether, chloroform, acetone, or alcohol) to an inconspicuous area of the suspect resin. This is a very useful test that can be applied before you purchase specimens of ? amber; and,
2. A yellow stain will be deposited on the surface of an alcohol-moistened white cloth or tissue, when an inconspicuous surface of kauri and/or copal is wiped briskly with a moistened cloth or tissue.
Polyberne
Polyberne, a man-made composite imitation of amber consists of fragments of amber embedded in brownish polyester casting resin. Polyberne is a distinctly Polish product that displays evidence of:
- Molding.
- Entrapment of air bubbles between the external surface of the imitation and the mold into which the polyester resin was poured.
- Evidence of two components. That is fragments of amber embedded in a resin of different refractive index.
Hand lens examination, looking for evidence of embedding and molding, and perhaps a test for sectility, are all that is required to positively identify the polyberne imitation of amber.
So beware, these materials are in the marketplace. Do not be caught for want of applying a few simple observations and tests.
Gemcraft: How To Cut And Polish Gemstones
By Lelande Quick and Hugh Leiper
Chilton Company
1959
Chilton Company writes:
For the hundreds of thousands of devotees now engaged in this relatively new craft, here are the newest and most comprehensive techniques and information based on the combined experience of two leading experts in the field.
Beginning with a description of the properties and physical characteristics of gems, including synthetics and imitations, the authors show the craftsman how to get started, the equipment needed, how to saw, grind, lap, sand, and polish. They cover the grinding and polishing of cabochons, the cutting and polishing of faceted stones, with a special helpful section on dopping, carving and sculpturing gemstones, mosaic and intarsia, plus special polishing problems of gemstones.
Gemstone novelties are also included, such as bookends, clocks, lamps, ashtrays, agate handled silverware, dishes, and many others. One of the highlights of Gemcraft is the chapter on where and how to collect gemstones. Indispensable for the collector, this section is packed with interesting information. The chapter on special lapidary techniques and shortcuts is very valuable. The many clear, step-by-step photographs presenting every important process in gemcraft and the extensive bibliography and complete index make this the finest, most thorough book on the subject published.
Chilton Company
1959
Chilton Company writes:
For the hundreds of thousands of devotees now engaged in this relatively new craft, here are the newest and most comprehensive techniques and information based on the combined experience of two leading experts in the field.
Beginning with a description of the properties and physical characteristics of gems, including synthetics and imitations, the authors show the craftsman how to get started, the equipment needed, how to saw, grind, lap, sand, and polish. They cover the grinding and polishing of cabochons, the cutting and polishing of faceted stones, with a special helpful section on dopping, carving and sculpturing gemstones, mosaic and intarsia, plus special polishing problems of gemstones.
Gemstone novelties are also included, such as bookends, clocks, lamps, ashtrays, agate handled silverware, dishes, and many others. One of the highlights of Gemcraft is the chapter on where and how to collect gemstones. Indispensable for the collector, this section is packed with interesting information. The chapter on special lapidary techniques and shortcuts is very valuable. The many clear, step-by-step photographs presenting every important process in gemcraft and the extensive bibliography and complete index make this the finest, most thorough book on the subject published.
Thursday, March 22, 2007
The Tutorial
(via Wahroongai News, Volume 32, Number 4, April 1998) Grahame Brown writes:
Traditional tutorials were one-to-one periods of instruction given by masters to students at university colleges. Today the role of the tutorial has been expanded to include those small group teaching sessions, of four or less students, that are primarily devoted to a critical and searching discussion of subject matter—but are particularly concerned with developing each student’s independent intellectual powers. The tutor’s principal task in a tutorial is to use subject matter to what he or she considers its best advantage to stimulate, develop, and maximize the individual student’s powers of thought, analysis, and self-expression.
In the tutorial the tutor’s role is likely to be a dominant one; for the tutor’s major task is to direct student understanding, and student learning. To that end, tutor’s must pose relevant searching questions, check and analyze student responses to those questions, and direct student learning to remedy any perceived errors of fact, concept, and/or analysis.
Tutorials serve three broad purposes in authority-based (as opposed to self-directed) learning:
- They provide a regular meeting place for checking student progress.
- They provide a very effective means for discovering misunderstandings in larger format methods of instruction, such as lectures and demonstrations to more than five individuals.
- They provide an opportunity for detailed scrutiny of a particular piece or aspect of the student’s work.
However, the much underrated pastoral role of the tutor never should be neglected; for the tutorial format offers the tutor a unique opportunity to inject some humanity into the educative process. Problems can be discovered, and suitable remedies suggested and implemented—taking into full consideration the personality of the student, their progress in their peer academic group, and any private matters that may or may not be affecting the student’s progress.
Advantages offered by the tutorial are that:
If focuses attention on the work of the individual student and his or her ways of thinking.
It allows the tutor to keep a close eye on each student’s progress.
It provides essential continuity in the tutor-student relationship.
Disadvantages of the tutorial are that:
It can be very demanding of time, both for the student and the tutor.
The tutor has a dominant role in the educative process.
Conclusion
Used intelligently and selectively the tutorial is an effective educational tool—provided tutors are knowledgeable, and adequately trained to pose the right questions required to stimulate the independent intellectual powers of the student. Of course, tutorials will fail if students do not think, research, write answers to the questions their tutors pose.
Traditional tutorials were one-to-one periods of instruction given by masters to students at university colleges. Today the role of the tutorial has been expanded to include those small group teaching sessions, of four or less students, that are primarily devoted to a critical and searching discussion of subject matter—but are particularly concerned with developing each student’s independent intellectual powers. The tutor’s principal task in a tutorial is to use subject matter to what he or she considers its best advantage to stimulate, develop, and maximize the individual student’s powers of thought, analysis, and self-expression.
In the tutorial the tutor’s role is likely to be a dominant one; for the tutor’s major task is to direct student understanding, and student learning. To that end, tutor’s must pose relevant searching questions, check and analyze student responses to those questions, and direct student learning to remedy any perceived errors of fact, concept, and/or analysis.
Tutorials serve three broad purposes in authority-based (as opposed to self-directed) learning:
- They provide a regular meeting place for checking student progress.
- They provide a very effective means for discovering misunderstandings in larger format methods of instruction, such as lectures and demonstrations to more than five individuals.
- They provide an opportunity for detailed scrutiny of a particular piece or aspect of the student’s work.
However, the much underrated pastoral role of the tutor never should be neglected; for the tutorial format offers the tutor a unique opportunity to inject some humanity into the educative process. Problems can be discovered, and suitable remedies suggested and implemented—taking into full consideration the personality of the student, their progress in their peer academic group, and any private matters that may or may not be affecting the student’s progress.
Advantages offered by the tutorial are that:
If focuses attention on the work of the individual student and his or her ways of thinking.
It allows the tutor to keep a close eye on each student’s progress.
It provides essential continuity in the tutor-student relationship.
Disadvantages of the tutorial are that:
It can be very demanding of time, both for the student and the tutor.
The tutor has a dominant role in the educative process.
Conclusion
Used intelligently and selectively the tutorial is an effective educational tool—provided tutors are knowledgeable, and adequately trained to pose the right questions required to stimulate the independent intellectual powers of the student. Of course, tutorials will fail if students do not think, research, write answers to the questions their tutors pose.
My Fair Lady
Memorable quote (s) from the movie:
Professor Henry Higgins (Rex Harrison): I know your head aches; I know you're tired; I know your nerves are as raw as meat in a butcher's window. But think what you're trying to accomplish. Think what you're dealing with. The majesty and grandeur of the English language, it's the greatest possession we have. The noblest thoughts that ever flowed through the hearts of men are contained in its extraordinary, imaginative, and musical mixtures of sounds. And that's what you've set yourself out to conquer Eliza. And conquer it you will.
Professor Henry Higgins (Rex Harrison): I know your head aches; I know you're tired; I know your nerves are as raw as meat in a butcher's window. But think what you're trying to accomplish. Think what you're dealing with. The majesty and grandeur of the English language, it's the greatest possession we have. The noblest thoughts that ever flowed through the hearts of men are contained in its extraordinary, imaginative, and musical mixtures of sounds. And that's what you've set yourself out to conquer Eliza. And conquer it you will.
Ageing Is When.......
(via Wahroongai News, Volume 24, No.6, June, 1990)
Everything hurts and what doesn’t hurt, doesn’t work.
You feel like the night after, and you haven’t been anywhere.
You get winded playing chess.
You little black book contains only names ending in M.D.
Your children begin to look middle-aged.
You’re still chasing women but can’t remember why.
You know all the answers, but nobody asks you the questions.
Your knees buckle and your belt won’t.
You stop looking forward to your next birthday.
You burn the midnight oil until 9:00 pm.
Everything hurts and what doesn’t hurt, doesn’t work.
You feel like the night after, and you haven’t been anywhere.
You get winded playing chess.
You little black book contains only names ending in M.D.
Your children begin to look middle-aged.
You’re still chasing women but can’t remember why.
You know all the answers, but nobody asks you the questions.
Your knees buckle and your belt won’t.
You stop looking forward to your next birthday.
You burn the midnight oil until 9:00 pm.
How Well Do You Know Jewelry?
(via JQ magazine, July/August 1996) Naaz Aalund writes:
The questions in this quiz have been gathered from experts in the jewelry industry as the most often asked questions. While some of the multiple choice answers contain correct information, the right answer is the one that concisely presents the best information to the customer.
Have fun.
1. Are platinum and white gold the same thing?
a. There is no true white gold
b. There is no difference—they are the same thing.
c. Platinum is a noble metal that is naturally white, while white gold is combined with zinc, nickel and silver to give the naturally yellow gold a white color.
d. Platinum is more rare, more pure, more dense and more demanding to work with, so it’s more expensive.
Answer: c
2. Are tanzanites too fragile to wear in rings?
a. No. Wear them all the time and don’t give it a second thought.
b. Yes. Tanzanite should only be worn in pendants and earrings.
c. Tanzanites are thermo-sensitive, so it is not advisable to wear them while cooking.
d. Tanzanites are 6.5 on the Moh’s hardness scale, which means if they are not cared for properly, they may get scratched. Opals are only a 6, and pearls are only a 3, so if they can be worn in rings, so can tanzanite.
Answer: d
3. With colored gemstones, is darker always better?
a. Intensity of color is all a matter of personal preference.
b. Intensity of color is good even if the gemstone is so dark that color and light can no longer be seen in it.
c. Actually, lighter is better—as with diamonds, colorless is best.
d. Intensity is good up to a point. When a gemstone becomes too dark, it is not as valuable.
Answer: d
4. Is eighteen karat gold too soft? Is fourteen karat gold stronger?
a. Only fourteen karat gold is tough enough to take daily wear.
b. High quality jewelry is made heavy enough for eighteen karat gold to be acceptable.
c. In tests done on eighteen karat and fourteen karat gold, both wore evenly under similar conditions, with fourteen karat showing cracking from fatigue more quickly than eighteen karat.
d. Fourteen karat is best for thin wire jewelry.
Answer: c
5. Are diamonds the rarest of gemstones?
a. De Beers maintains a limited supply and keeps demand high with advertising.
b. Rarity is dependent on many factors, including color, carat weight and clarity. Often a ruby, spinel, or tsavorite of exceptional quality will be more rare than an average diamond.
c. A ‘D’ color flawless diamond is not only the rarest of diamonds; it is also the most rare of all gemstones.
d. Rarity of a gemstone is dependent upon whether the gemstones can be made in a laboratory.
Answer: b
6. Can a ring be sized to any size, larger or smaller?
a. No problem. Gold is a very flexible metal, and it can be bent easily.
b. A ring can be sized smaller much more easily than it can be sized larger.
c. The goldsmiths can compress or stretch the gold as needed to make a ring smaller or larger.
d. Sizing a ring more than two sizes larger or smaller may structurally damage the ring and cause gemstones to break or fall out.
Answer: d
7. What is the difference between precious and semi-precious gemstones?
a. Precious gemstones are diamond, ruby, emerald and sapphire; everything else is semi-precious.
b. Rarity and beauty determine a gemstone’s value. An extremely large Paraiba tourmaline would be more valuable, and thus more precious, than a pale and included emerald. These terms precious and semi-precious do not truly indicate a gemstone’s value.
c. Semi-precious gemstones include cubic zirconia, synthetic sapphires and emeralds and all laboratory grown gemstones, while precious gemstones are all natural.
d. Precious gemstones are the twelve birthstones, one for each month of the year, and semi-precious are the gemstones that aren’t birthstones.
Answer: b
8. Why is platinum jewelry so much more expensive than gold?
a. Platinum is more demanding to work with, so it requires greater skill in manufacturing, making labor more expensive.
b. Platinum is twice as dense as fourteen carat gold. In jewelry that is the same size and shape, platinum will weigh more, making it more expensive.
c. Platinum is 90 percent pure platinum. Whereas fourteen carat gold is only 58 percent pure gold, platinum is alloyed with iridium, another platinum-family metal which keeps its value high.
d. All of the above.
Answer: d
9. Why does it take 4-6 weeks to custom-make a jewelry item?
a. At any given time, a designer and his staff may be making 200 pieces of jewelry or more, so for a client’s job to get the attention it needs, other work must be cleared away first.
b. In each step of the jewelry making process, there is a specialist that must complete her part of the job to the best of her abilities for the jewelry item to have the high quality of craftsmanship the client deserves.
c. Jewelry is still in large part made by hand by craftsmen and women who have practiced their craft for a lifetime to achieve mastery. Yet even the finest master craftsperson, when rushed, may overlook flaws that compromise quality.
d. All of the above.
Answer: d
10. Why can’t I wear my jewelry all the time? If it’s good quality jewelry, shouldn’t it last even when I wear it during sports and to bed?
a. Jewelry last hundreds of years and never wears out. Don’t worry about wearing your jewelry all the time.
b. Like a fine silk blouse or a mink coat, jewelry and gemstones can be damaged if not cared for and worn properly.
c. The investment you have made in your jewelry will be lost if you wear it in way that will damage it.
d. Like everything that is around us, things will wear out and, unfortunately, jewelry is no exception. To minimize the wear and tear that can detract from your jewelry’s longevity and beauty, it is advisable to remove it during activities and at bedtime.
e. Answers b & d.
Answer: e
The questions in this quiz have been gathered from experts in the jewelry industry as the most often asked questions. While some of the multiple choice answers contain correct information, the right answer is the one that concisely presents the best information to the customer.
Have fun.
1. Are platinum and white gold the same thing?
a. There is no true white gold
b. There is no difference—they are the same thing.
c. Platinum is a noble metal that is naturally white, while white gold is combined with zinc, nickel and silver to give the naturally yellow gold a white color.
d. Platinum is more rare, more pure, more dense and more demanding to work with, so it’s more expensive.
Answer: c
2. Are tanzanites too fragile to wear in rings?
a. No. Wear them all the time and don’t give it a second thought.
b. Yes. Tanzanite should only be worn in pendants and earrings.
c. Tanzanites are thermo-sensitive, so it is not advisable to wear them while cooking.
d. Tanzanites are 6.5 on the Moh’s hardness scale, which means if they are not cared for properly, they may get scratched. Opals are only a 6, and pearls are only a 3, so if they can be worn in rings, so can tanzanite.
Answer: d
3. With colored gemstones, is darker always better?
a. Intensity of color is all a matter of personal preference.
b. Intensity of color is good even if the gemstone is so dark that color and light can no longer be seen in it.
c. Actually, lighter is better—as with diamonds, colorless is best.
d. Intensity is good up to a point. When a gemstone becomes too dark, it is not as valuable.
Answer: d
4. Is eighteen karat gold too soft? Is fourteen karat gold stronger?
a. Only fourteen karat gold is tough enough to take daily wear.
b. High quality jewelry is made heavy enough for eighteen karat gold to be acceptable.
c. In tests done on eighteen karat and fourteen karat gold, both wore evenly under similar conditions, with fourteen karat showing cracking from fatigue more quickly than eighteen karat.
d. Fourteen karat is best for thin wire jewelry.
Answer: c
5. Are diamonds the rarest of gemstones?
a. De Beers maintains a limited supply and keeps demand high with advertising.
b. Rarity is dependent on many factors, including color, carat weight and clarity. Often a ruby, spinel, or tsavorite of exceptional quality will be more rare than an average diamond.
c. A ‘D’ color flawless diamond is not only the rarest of diamonds; it is also the most rare of all gemstones.
d. Rarity of a gemstone is dependent upon whether the gemstones can be made in a laboratory.
Answer: b
6. Can a ring be sized to any size, larger or smaller?
a. No problem. Gold is a very flexible metal, and it can be bent easily.
b. A ring can be sized smaller much more easily than it can be sized larger.
c. The goldsmiths can compress or stretch the gold as needed to make a ring smaller or larger.
d. Sizing a ring more than two sizes larger or smaller may structurally damage the ring and cause gemstones to break or fall out.
Answer: d
7. What is the difference between precious and semi-precious gemstones?
a. Precious gemstones are diamond, ruby, emerald and sapphire; everything else is semi-precious.
b. Rarity and beauty determine a gemstone’s value. An extremely large Paraiba tourmaline would be more valuable, and thus more precious, than a pale and included emerald. These terms precious and semi-precious do not truly indicate a gemstone’s value.
c. Semi-precious gemstones include cubic zirconia, synthetic sapphires and emeralds and all laboratory grown gemstones, while precious gemstones are all natural.
d. Precious gemstones are the twelve birthstones, one for each month of the year, and semi-precious are the gemstones that aren’t birthstones.
Answer: b
8. Why is platinum jewelry so much more expensive than gold?
a. Platinum is more demanding to work with, so it requires greater skill in manufacturing, making labor more expensive.
b. Platinum is twice as dense as fourteen carat gold. In jewelry that is the same size and shape, platinum will weigh more, making it more expensive.
c. Platinum is 90 percent pure platinum. Whereas fourteen carat gold is only 58 percent pure gold, platinum is alloyed with iridium, another platinum-family metal which keeps its value high.
d. All of the above.
Answer: d
9. Why does it take 4-6 weeks to custom-make a jewelry item?
a. At any given time, a designer and his staff may be making 200 pieces of jewelry or more, so for a client’s job to get the attention it needs, other work must be cleared away first.
b. In each step of the jewelry making process, there is a specialist that must complete her part of the job to the best of her abilities for the jewelry item to have the high quality of craftsmanship the client deserves.
c. Jewelry is still in large part made by hand by craftsmen and women who have practiced their craft for a lifetime to achieve mastery. Yet even the finest master craftsperson, when rushed, may overlook flaws that compromise quality.
d. All of the above.
Answer: d
10. Why can’t I wear my jewelry all the time? If it’s good quality jewelry, shouldn’t it last even when I wear it during sports and to bed?
a. Jewelry last hundreds of years and never wears out. Don’t worry about wearing your jewelry all the time.
b. Like a fine silk blouse or a mink coat, jewelry and gemstones can be damaged if not cared for and worn properly.
c. The investment you have made in your jewelry will be lost if you wear it in way that will damage it.
d. Like everything that is around us, things will wear out and, unfortunately, jewelry is no exception. To minimize the wear and tear that can detract from your jewelry’s longevity and beauty, it is advisable to remove it during activities and at bedtime.
e. Answers b & d.
Answer: e
Dictionary Of Australian Gemstones
Edited by Bill Myatt
Paul Hamlyn Pty Ltd
1974 ISBN 0-600-07240-1
Paul Hamlyn writes:
The glow of Australian dazzling variety of gemstones reflects from the pages of this specialist dictionary. From the thunder egg in the agate family to the majesty of the black opal…from flawless emeralds to the brilliant fire of zircon…the range reflects excitement and beauty. Accompanied by 75 color pictures, the Dictionary of Australian Gemstones provides a comprehensive guide to our exquisite treasures. And more than this, you will learn how to fossick and claim some of these treasures for yourself. You will learn too how to turn the raw beauty you find into jewelry.
The Dictionary of Australian Gemstones is rich reading with the promise of rich rewards.
Paul Hamlyn Pty Ltd
1974 ISBN 0-600-07240-1
Paul Hamlyn writes:
The glow of Australian dazzling variety of gemstones reflects from the pages of this specialist dictionary. From the thunder egg in the agate family to the majesty of the black opal…from flawless emeralds to the brilliant fire of zircon…the range reflects excitement and beauty. Accompanied by 75 color pictures, the Dictionary of Australian Gemstones provides a comprehensive guide to our exquisite treasures. And more than this, you will learn how to fossick and claim some of these treasures for yourself. You will learn too how to turn the raw beauty you find into jewelry.
The Dictionary of Australian Gemstones is rich reading with the promise of rich rewards.
Wednesday, March 21, 2007
Chiastolite
(via Wahroongai News, Volume 24, No.3, March 1990) Australian Amateur Mineralogist writes:
One of the most intriguing minerals found in interior Australia is the chiastolite of Australian Cross Stone. In nature, the mineral occurs as cigar-shaped crystals in slates which have been ‘heat treated’ by invading granites. Crystals mostly average about 3 or 4 inches in length by an inch in diameter. As they weather from their micaceous (schistose) host rock, they have little obvious beauty. Their shape alone may attract attention.
When broken, an internal cross from is revealed traced in shades of gray, white and sometimes a delicate pink. When cut and polished, true gem status is achieved, and selected examples were once quite popular in the jewelry trade. Like most Australian gem industries, however, indiscrete swamping of markets, careless preparation, and lack of suitable advertising propaganda ruined any wide market possibilities even before they materialized. Its fate was a dismal as the Harts Range ‘rubies’ (or garnet). Even opal had from time to time suffered from similar Australian carelessness. Opal, however, now seems to be enjoying more rewarding popularity on its own merits.
Chiastolites of good internal form occur in but few places in the world, and of these the Bimbowrie Station examples from the Olary district in South Australia undoubtedly are of outstanding quality. At one time, fine specimens could be collected in quality strewn about the slopes of the low schistose hills of the locality. Shearers passing by repeatedly collected them in sugarbags full and returned them to their friends and relatives in the cities. They received wide appeal, but after a time their very abundance weighed against them. Now the picture is different. The old localities are largely worked out as far as surface occurrences are concerned. A day’s collecting will certainly provide many tens of pounds of them, but good ones are no longer over plentiful. Now it appears the stage may be set for real appreciation. The jewelry trade will soon realize their potential.
The origin of these freaks of nature, as indeed they are, is interesting. The mineral is a form of andalusite, a relatively common mineral in the field. In composition, it is a silicate of aluminum, or chemically, Al2SiO5. The reason for its interest is, of course, the cruciform internal structure—a factor of interest, particularly in matters of Christian religion—but also for beauty in its own right.
The cross structure is related to the method of growth of the individual crystal in the presence of minute amounts of carbon as impurities in the enclosing rock medium. The crystals actually grow at the expense of the enclosing aluminous sediment—a redistribution of the alumina and silica of the argillaceous slate occurring to form the crystals. In the present examples small amounts of carbonaceous material occur along with these substances which are excess to the growing crystals requirements. The effects of solution and heat responsible for the minerals growth were not sufficient to remove the carbonaceous matter so they were just pushed aside into less inconvenient situations with in the developing crystal structure.
In this way, the square form of the crystal in section (the mineral crystallizes in the orthorhombic system) imposes a cruciform distribution of the reconcentrated carbon material and leaves other areas relatively free of this substance, and therefore lighter in color.
Actually, the crystal effects redistribution of the carbon in two major patterns, both of which form ‘crosses’ of a type. One is called the ‘Howdenite’ after Mr J Howden, their prospector-discoverer, and the other is unnamed.
Prof Mawson, in his writings on ‘The Geology of the Broken Hill Area’, has dealt with this subject in great detail and earlier in this century produced excellent color reproductions of them. He, too saw their gem potential, and felt that they should have been developed to greater advantage. Perhaps one day we will appreciate them as they deserve, and our ladies will choose them in preference to artificial gems as charms and pendant adornments. I think we shall……….
One of the most intriguing minerals found in interior Australia is the chiastolite of Australian Cross Stone. In nature, the mineral occurs as cigar-shaped crystals in slates which have been ‘heat treated’ by invading granites. Crystals mostly average about 3 or 4 inches in length by an inch in diameter. As they weather from their micaceous (schistose) host rock, they have little obvious beauty. Their shape alone may attract attention.
When broken, an internal cross from is revealed traced in shades of gray, white and sometimes a delicate pink. When cut and polished, true gem status is achieved, and selected examples were once quite popular in the jewelry trade. Like most Australian gem industries, however, indiscrete swamping of markets, careless preparation, and lack of suitable advertising propaganda ruined any wide market possibilities even before they materialized. Its fate was a dismal as the Harts Range ‘rubies’ (or garnet). Even opal had from time to time suffered from similar Australian carelessness. Opal, however, now seems to be enjoying more rewarding popularity on its own merits.
Chiastolites of good internal form occur in but few places in the world, and of these the Bimbowrie Station examples from the Olary district in South Australia undoubtedly are of outstanding quality. At one time, fine specimens could be collected in quality strewn about the slopes of the low schistose hills of the locality. Shearers passing by repeatedly collected them in sugarbags full and returned them to their friends and relatives in the cities. They received wide appeal, but after a time their very abundance weighed against them. Now the picture is different. The old localities are largely worked out as far as surface occurrences are concerned. A day’s collecting will certainly provide many tens of pounds of them, but good ones are no longer over plentiful. Now it appears the stage may be set for real appreciation. The jewelry trade will soon realize their potential.
The origin of these freaks of nature, as indeed they are, is interesting. The mineral is a form of andalusite, a relatively common mineral in the field. In composition, it is a silicate of aluminum, or chemically, Al2SiO5. The reason for its interest is, of course, the cruciform internal structure—a factor of interest, particularly in matters of Christian religion—but also for beauty in its own right.
The cross structure is related to the method of growth of the individual crystal in the presence of minute amounts of carbon as impurities in the enclosing rock medium. The crystals actually grow at the expense of the enclosing aluminous sediment—a redistribution of the alumina and silica of the argillaceous slate occurring to form the crystals. In the present examples small amounts of carbonaceous material occur along with these substances which are excess to the growing crystals requirements. The effects of solution and heat responsible for the minerals growth were not sufficient to remove the carbonaceous matter so they were just pushed aside into less inconvenient situations with in the developing crystal structure.
In this way, the square form of the crystal in section (the mineral crystallizes in the orthorhombic system) imposes a cruciform distribution of the reconcentrated carbon material and leaves other areas relatively free of this substance, and therefore lighter in color.
Actually, the crystal effects redistribution of the carbon in two major patterns, both of which form ‘crosses’ of a type. One is called the ‘Howdenite’ after Mr J Howden, their prospector-discoverer, and the other is unnamed.
Prof Mawson, in his writings on ‘The Geology of the Broken Hill Area’, has dealt with this subject in great detail and earlier in this century produced excellent color reproductions of them. He, too saw their gem potential, and felt that they should have been developed to greater advantage. Perhaps one day we will appreciate them as they deserve, and our ladies will choose them in preference to artificial gems as charms and pendant adornments. I think we shall……….
Sideways
Memorable quote (s) from the movie:
Miles Raymond (Paul Giamatti): What about you?
Maya (Virginia Madsen): What about me?
Miles Raymond (Paul Giamatti): I don't know. Why are you into wine?
Maya (Virginia Madsen): Oh I... I think I... I originally got in to wine through my ex-husband.
Miles Raymond (Paul Giamatti): Ah.
Maya (Virginia Madsen): You know, he had this big, sort of show-off cellar, you know.
Miles Raymond (Paul Giamatti): Right.
Maya (Virginia Madsen): But then I discovered that I had a really sharp palate.
Miles Raymond (Paul Giamatti):Uh-huh.
Maya (Virginia Madsen): And the more I drank, the more I liked what it made me think about.
Miles Raymond (Paul Giamatti): Like what?
Maya (Virginia Madsen): Like what a fraud he was. No, I- I like to think about the life of wine.
Miles Raymond (Paul Giamatti):Yeah.
Maya (Virginia Madsen): How it's a living thing. I like to think about what was going on the year the grapes were growing; how the sun was shining; if it rained. I like to think about all the people who tended and picked the grapes. And if it's an old wine, how many of them must be dead by now. I like how wine continues to evolve, like if I opened a bottle of wine today it would taste different than if I'd opened it on any other day, because a bottle of wine is actually alive. And it's constantly evolving and gaining complexity. That is, until it peaks, like your '61. And then it begins its steady, inevitable decline.
Miles Raymond (Paul Giamatti): Hmm.
Maya (Virginia Madsen): And it tastes so fucking good.
Miles Raymond (Paul Giamatti): What about you?
Maya (Virginia Madsen): What about me?
Miles Raymond (Paul Giamatti): I don't know. Why are you into wine?
Maya (Virginia Madsen): Oh I... I think I... I originally got in to wine through my ex-husband.
Miles Raymond (Paul Giamatti): Ah.
Maya (Virginia Madsen): You know, he had this big, sort of show-off cellar, you know.
Miles Raymond (Paul Giamatti): Right.
Maya (Virginia Madsen): But then I discovered that I had a really sharp palate.
Miles Raymond (Paul Giamatti):Uh-huh.
Maya (Virginia Madsen): And the more I drank, the more I liked what it made me think about.
Miles Raymond (Paul Giamatti): Like what?
Maya (Virginia Madsen): Like what a fraud he was. No, I- I like to think about the life of wine.
Miles Raymond (Paul Giamatti):Yeah.
Maya (Virginia Madsen): How it's a living thing. I like to think about what was going on the year the grapes were growing; how the sun was shining; if it rained. I like to think about all the people who tended and picked the grapes. And if it's an old wine, how many of them must be dead by now. I like how wine continues to evolve, like if I opened a bottle of wine today it would taste different than if I'd opened it on any other day, because a bottle of wine is actually alive. And it's constantly evolving and gaining complexity. That is, until it peaks, like your '61. And then it begins its steady, inevitable decline.
Miles Raymond (Paul Giamatti): Hmm.
Maya (Virginia Madsen): And it tastes so fucking good.
About Birthstones
(via Wahroongai News, Volume 24, No.9, September 1990)
In ancient Egypt, there was an accepted custom of engraving symbols onto certain semi-precious gemstones which had been cut into various symbolical forms. These symbols were taken from a very ancient ritual composition called the Book of the Dead. The symbols were inscribed on exceptional pieces of emerald in matrix, green and red jasper, malachite, lapis lazuli, feldspar, serpentine, turquoise, and carnelian. They were hand-carved in the form of heart-shaped amulets and beetle-shaped scarabs. The ancient symbols were usually inlaid with gold with ornamental gold surrounding the amulets and scarabs. These carved gems were usually placed around the neck of a mummy to assure safe passage of the soul of the deceased through the realm of the dead and to insure protection from all evil influences. One particular amulet called ‘uat’ insured that the deceased would enjoy eternal youth in the realm of the dead. There were many other amulets and scarabs, each with their own unique supernatural powers.
Beginning in the first century A.D., the writings of the Jewish historian Josephus (37 – 95 A.D) set forth the belief that to each month of the year a special stone was dedicated and that the stone of the month was endowed with a particular virtue for those born in that month. This was called their ‘natal’ stone, later to become known as birthstones. However, it was not until the 18th century in Poland that the wearing of natal or birthstones became an accepted custom. This disparity in time and custom may be attributed to the fact that the special virtues of the gemstone were customarily accepted. But is was centuries before what many believed to be a mystic bond between the stone of the month and the person born in that month was fully realized.
Each stone had particularly strong powers for the person born during its month. This belief grew from early studies of the Bible, in particular, the book of Exodus (28: 17 – 20) and Revelation (21: 19, 20). Although the special powers of gemstones were generally accepted, the practice of wearing birthstones attributed to the influence of Jewish rabbis and gem traders who settled there.
Today, the wearing of birthstones is an accepted custom. They are worn now not for their supposed mythical powers, but rather because of their color, brilliance, and beauty.
In ancient Egypt, there was an accepted custom of engraving symbols onto certain semi-precious gemstones which had been cut into various symbolical forms. These symbols were taken from a very ancient ritual composition called the Book of the Dead. The symbols were inscribed on exceptional pieces of emerald in matrix, green and red jasper, malachite, lapis lazuli, feldspar, serpentine, turquoise, and carnelian. They were hand-carved in the form of heart-shaped amulets and beetle-shaped scarabs. The ancient symbols were usually inlaid with gold with ornamental gold surrounding the amulets and scarabs. These carved gems were usually placed around the neck of a mummy to assure safe passage of the soul of the deceased through the realm of the dead and to insure protection from all evil influences. One particular amulet called ‘uat’ insured that the deceased would enjoy eternal youth in the realm of the dead. There were many other amulets and scarabs, each with their own unique supernatural powers.
Beginning in the first century A.D., the writings of the Jewish historian Josephus (37 – 95 A.D) set forth the belief that to each month of the year a special stone was dedicated and that the stone of the month was endowed with a particular virtue for those born in that month. This was called their ‘natal’ stone, later to become known as birthstones. However, it was not until the 18th century in Poland that the wearing of natal or birthstones became an accepted custom. This disparity in time and custom may be attributed to the fact that the special virtues of the gemstone were customarily accepted. But is was centuries before what many believed to be a mystic bond between the stone of the month and the person born in that month was fully realized.
Each stone had particularly strong powers for the person born during its month. This belief grew from early studies of the Bible, in particular, the book of Exodus (28: 17 – 20) and Revelation (21: 19, 20). Although the special powers of gemstones were generally accepted, the practice of wearing birthstones attributed to the influence of Jewish rabbis and gem traders who settled there.
Today, the wearing of birthstones is an accepted custom. They are worn now not for their supposed mythical powers, but rather because of their color, brilliance, and beauty.
World's Poor Represent $5 trillion Market
(via news/yahoo) IFC writes:
The world's estimated four billion people who live under the poverty line represent an untapped global market worth $5 trillion in local purchasing power, according to a new report.
The report by the International Financial Corp., the World Bank's private sector arm, and environmental think-tank the World Resources Institute, measures the size of the market using income and expenditure from household surveys. It comes as domestic and multinational corporations look closer at breaking into this under-served markets, where microlending is already a mushrooming business.
Development projects have focused on the poorest of the poor, but a much larger group are families with incomes below $3,000 a year, who mainly work in the informal sector, have no bank accounts or access to modern financial services, and lack access to clean water, electricity and basic health care.
The report "The Next Four Billion: Market Size and Business Strategy at the Base of the Pyramid," refers to this group as the base of the pyramid markets, or BOP. A wealthier mid-tier group with per capita incomes between $3,000 and $20,000 represents a global market worth $12.5 trillion, but they are better off in general, living mainly in cities and are better served.
"The report backs up the calls for broader business engagement with the base of the pyramid, stressing the need for the private sector to play a greater role in development," said Michael Klein, the IFC's chief economist.
"The report also highlights the need for governments to pick up the pace of reforms to the operating and regulatory environment, so that it becomes easier to do business," he added.
The BOP market is by far the largest in Asia and the Middle East, reflecting the sheer weight of the population, with 2.86 billion people with an aggregate income of $3.47 trillion.
In Eastern Europe, the BOP market totals $458 billion and includes 254 million people, or 64 percent of the region's population, with 36 percent of its aggregate purchasing power. In Latin America, this segment is estimated to include $509 billion and 360 million people, which is 70 percent of the region's population but only 28 percent aggregate purchasing power. In Africa, the BOP market is smaller at $429 billion, but it is by far the dominant consumer market on the continent, representing 71 percent of aggregate purchasing power in the region.
In surveys that look at sector markets for the 4 billion consumers, the report said range from $20 billion for water, $51 billion for technology, $158 billion for health, $433 billion for energy and the largest is $2.89 trillion for food.
According to surveys more than half of these poor households' health care spending is for pharmaceuticals. As incomes rise, the share of household spending for food declines, while the share of spending for transportation and for phone and Internet access rises sharply. For all developing regions except Eastern Europe, firewood is the main cooking fuel, while propane or other modern fuels dominate dominate higher-income segments and urban areas.
The world's estimated four billion people who live under the poverty line represent an untapped global market worth $5 trillion in local purchasing power, according to a new report.
The report by the International Financial Corp., the World Bank's private sector arm, and environmental think-tank the World Resources Institute, measures the size of the market using income and expenditure from household surveys. It comes as domestic and multinational corporations look closer at breaking into this under-served markets, where microlending is already a mushrooming business.
Development projects have focused on the poorest of the poor, but a much larger group are families with incomes below $3,000 a year, who mainly work in the informal sector, have no bank accounts or access to modern financial services, and lack access to clean water, electricity and basic health care.
The report "The Next Four Billion: Market Size and Business Strategy at the Base of the Pyramid," refers to this group as the base of the pyramid markets, or BOP. A wealthier mid-tier group with per capita incomes between $3,000 and $20,000 represents a global market worth $12.5 trillion, but they are better off in general, living mainly in cities and are better served.
"The report backs up the calls for broader business engagement with the base of the pyramid, stressing the need for the private sector to play a greater role in development," said Michael Klein, the IFC's chief economist.
"The report also highlights the need for governments to pick up the pace of reforms to the operating and regulatory environment, so that it becomes easier to do business," he added.
The BOP market is by far the largest in Asia and the Middle East, reflecting the sheer weight of the population, with 2.86 billion people with an aggregate income of $3.47 trillion.
In Eastern Europe, the BOP market totals $458 billion and includes 254 million people, or 64 percent of the region's population, with 36 percent of its aggregate purchasing power. In Latin America, this segment is estimated to include $509 billion and 360 million people, which is 70 percent of the region's population but only 28 percent aggregate purchasing power. In Africa, the BOP market is smaller at $429 billion, but it is by far the dominant consumer market on the continent, representing 71 percent of aggregate purchasing power in the region.
In surveys that look at sector markets for the 4 billion consumers, the report said range from $20 billion for water, $51 billion for technology, $158 billion for health, $433 billion for energy and the largest is $2.89 trillion for food.
According to surveys more than half of these poor households' health care spending is for pharmaceuticals. As incomes rise, the share of household spending for food declines, while the share of spending for transportation and for phone and Internet access rises sharply. For all developing regions except Eastern Europe, firewood is the main cooking fuel, while propane or other modern fuels dominate dominate higher-income segments and urban areas.
Classic Mineral Localities Of The World: Asia And Australia
By Philip Scalisi and David Cook
Van Nostrand Reinhold Company
1983 ISBN 0-442-28685-6
Van Nostrand Reinhold Company writes:
Although we’ve been stripping classic mineral deposits for years, many of them are not even close to depletion. What’s more, new and promising repositories of valuable minerals have been discovered only recently.
Now you’ll find stimulating facts about the classic mineral and gem localities of Asia and Australia in this first volume of a series that analyzes these areas throughout the world. Accounts by mineral experts, and a bounty of illustrations confirm this volume as an all-encompassing reference that will fast become the standard in the field.
Classic Mineral Localities of the World skillfully probes geographical sites where some of the finest examples of mineral species have been uncovered. Featured maps, crystal drawings, and photographs of gems and mineral specimens are from the famous Harvard University collection and other esteemed private collections. You’ll also see plates of fine quality representative mineral specimens and gems.
The gem and mineral localities of the U.S.S.R—the Ural Mountains and Siberia—and modern classic localities—the Nuristan District of Afghanistan, Reaphook Hill in South Australia, and Yinnietharra in Western Australia—are among the areas thoroughly evaluated. Sections of Japan, China, Burma, Sri Lanka, and Iran are also explored. Extensive descriptions of the diamond mines of India are included, in addition to one of the most complete listings of all well-known Indian diamonds.
Crystallographers, professional mineralogists, geologists, and gemologists as well as gem and mineral collectors and hobbyists should have this unique handbook for its indispensable reference material.
Van Nostrand Reinhold Company
1983 ISBN 0-442-28685-6
Van Nostrand Reinhold Company writes:
Although we’ve been stripping classic mineral deposits for years, many of them are not even close to depletion. What’s more, new and promising repositories of valuable minerals have been discovered only recently.
Now you’ll find stimulating facts about the classic mineral and gem localities of Asia and Australia in this first volume of a series that analyzes these areas throughout the world. Accounts by mineral experts, and a bounty of illustrations confirm this volume as an all-encompassing reference that will fast become the standard in the field.
Classic Mineral Localities of the World skillfully probes geographical sites where some of the finest examples of mineral species have been uncovered. Featured maps, crystal drawings, and photographs of gems and mineral specimens are from the famous Harvard University collection and other esteemed private collections. You’ll also see plates of fine quality representative mineral specimens and gems.
The gem and mineral localities of the U.S.S.R—the Ural Mountains and Siberia—and modern classic localities—the Nuristan District of Afghanistan, Reaphook Hill in South Australia, and Yinnietharra in Western Australia—are among the areas thoroughly evaluated. Sections of Japan, China, Burma, Sri Lanka, and Iran are also explored. Extensive descriptions of the diamond mines of India are included, in addition to one of the most complete listings of all well-known Indian diamonds.
Crystallographers, professional mineralogists, geologists, and gemologists as well as gem and mineral collectors and hobbyists should have this unique handbook for its indispensable reference material.
Tuesday, March 20, 2007
Diamonds, Stones To Grab Further Share In Jewellery Market
(via PTI) Economic Times writes:
Diamonds and gemstones jewellery are set to grab a greater market share from plain gold and silver ornaments with prices likely to come down after import duty cuts proposed in this year's union budget, making them more affordable for Indians.
Studded jewellery has already been taking some market share from plain gold and silver jewellery over the recent years and the proposed duty cuts are likely to further scale up their demand in the Indian market, global metal consultancy firm GFMS says in its latest report.
"With the reductions in import duties on precious stones, the domestic studded jewellery would become more affordable for consumers," GFMS metal analyst Sanjiv Arole said.
India is already the world's third largest consumer of diamond jewellery after the US and Japan and a further drop in prices could precipitate some important changes in jewellery consumption patterns in the near future, GFMS said.
The production of laboratory-manufactured diamonds is also likely to increase dramatically in the coming years, it added. While lab-manufactured diamonds appear quite identical to the natural diamonds, they cost about 70 per cent less.
India, as the largest cutting and polishing centre, is likely to become one of the key regions for processing these stones and this business would ultimately find its place in the domestic jewellery markets like Surat and elsewhere in the country.
Finance Minister P Chidambaram proposed in this year's budget to reduce import duties on cut and polished diamonds, coloured stones and corals.
While coloured stones or gems are also gaining popularity among consumers, their gains are unlikely at the expense of diamonds which are showing robust growth across most of the global markets. India is one of the fastest growing diamond markets in the world yet branded diamonds segment accounts for a meagre 12 per cent. The size of the overall diamond market in India is supposed to be over 1 billion dollar. Diamonds are gradually becoming a fashion purchase with branded segment having an edge over unbranded jewellery.
Diamonds and gemstones jewellery are set to grab a greater market share from plain gold and silver ornaments with prices likely to come down after import duty cuts proposed in this year's union budget, making them more affordable for Indians.
Studded jewellery has already been taking some market share from plain gold and silver jewellery over the recent years and the proposed duty cuts are likely to further scale up their demand in the Indian market, global metal consultancy firm GFMS says in its latest report.
"With the reductions in import duties on precious stones, the domestic studded jewellery would become more affordable for consumers," GFMS metal analyst Sanjiv Arole said.
India is already the world's third largest consumer of diamond jewellery after the US and Japan and a further drop in prices could precipitate some important changes in jewellery consumption patterns in the near future, GFMS said.
The production of laboratory-manufactured diamonds is also likely to increase dramatically in the coming years, it added. While lab-manufactured diamonds appear quite identical to the natural diamonds, they cost about 70 per cent less.
India, as the largest cutting and polishing centre, is likely to become one of the key regions for processing these stones and this business would ultimately find its place in the domestic jewellery markets like Surat and elsewhere in the country.
Finance Minister P Chidambaram proposed in this year's budget to reduce import duties on cut and polished diamonds, coloured stones and corals.
While coloured stones or gems are also gaining popularity among consumers, their gains are unlikely at the expense of diamonds which are showing robust growth across most of the global markets. India is one of the fastest growing diamond markets in the world yet branded diamonds segment accounts for a meagre 12 per cent. The size of the overall diamond market in India is supposed to be over 1 billion dollar. Diamonds are gradually becoming a fashion purchase with branded segment having an edge over unbranded jewellery.
Bonnie and Clyde
Memorable quote (s) from the movie:
Buck Barrow (Gene Hackman): Hey, you wanna hear a story 'bout this boy? He owned a dairy farm, see. And his ol' Ma, she was kinda sick, you know. And the doctor, he had called him come over, and said, uh, "Uhh listen, your Ma, she's lyin' there, she's just so sick and she's weakly, and uh, uh I want ya to try to persuade her to take a little brandy," you see. Just to pick her spirits up, ya know. And "Ma's a teetotaler," he says. "She wouldn't touch a drop." "Well, I'll tell ya whatcha do, uh," - the doc - "I'll tell ya whatcha do, you bring in a fresh quart of milk every day and you put some brandy in it, see. And see. You try that." So he did. And he doctored it all up with the brandy, fresh milk, and he gave it to his Mom. And she drank a little bit of it, you know. So next day, he brought it in again and she drank a little more, you know. And so they went on that way for the third day and just a little more, and the fourth day, she was, you know, took a little bit more - and then finally, one week later, he gave her the milk and she just drank it down. Boy, she swallowed the whole, whole, whole thing, you know. And she called him over and she said, "Son, whatever you do, don't sell that cow!"
Buck Barrow (Gene Hackman): Hey, you wanna hear a story 'bout this boy? He owned a dairy farm, see. And his ol' Ma, she was kinda sick, you know. And the doctor, he had called him come over, and said, uh, "Uhh listen, your Ma, she's lyin' there, she's just so sick and she's weakly, and uh, uh I want ya to try to persuade her to take a little brandy," you see. Just to pick her spirits up, ya know. And "Ma's a teetotaler," he says. "She wouldn't touch a drop." "Well, I'll tell ya whatcha do, uh," - the doc - "I'll tell ya whatcha do, you bring in a fresh quart of milk every day and you put some brandy in it, see. And see. You try that." So he did. And he doctored it all up with the brandy, fresh milk, and he gave it to his Mom. And she drank a little bit of it, you know. So next day, he brought it in again and she drank a little more, you know. And so they went on that way for the third day and just a little more, and the fourth day, she was, you know, took a little bit more - and then finally, one week later, he gave her the milk and she just drank it down. Boy, she swallowed the whole, whole, whole thing, you know. And she called him over and she said, "Son, whatever you do, don't sell that cow!"
A Perspective On Literacy
(via TJA 29, 62, 1979) I M Darveniza writes:
1. What is literacy?
What is literacy and why do we need a perspective on it? The term has been the subject of much debate in recent years but rarely is a definition attempted. First, literacy does not just mean reading. The Concise Oxford Dictionary defines literacy as ‘the ability to read and write’. If we add to this the ability to speak our native language concisely and fluently and to listen effectively to others speaking it, we come nearer to the broader meaning of literacy; the mastery of our native language in all its aspects, as a means of communication. The mastery of these four interrelated skills, reading, writing, speaking and listening, is a long term process and an extensive program of training at all ages is necessary.
2. How to read?
Reading a text chapter once is not enough. Most students retain less than 25% of a chapter’s contents after one reading. A better method is to spend a few minutes skimming through the chapter, noting topic headings, charts and italics and reading the summary. This will give an overview of the contents and prepare for a more thorough reading. Next, turn the topic headings into questions and read for the answers. Test by trying to recall the answers. Selectively review by re-reading these sections which are not clear. If underlining is to be done, it should be done at this stage and not during the first reading of the chapter. The final step is the brief outline of the chapter.
Reading Professional Journal
Students should have the foundations of continuing education fostered through the reading of professional journals. But professional journals are voluminous and many, and a word by word reading of the relevant seeming articles is tedious and time wasting. A suggested plan to attack for keeping abreast with current papers follows:
Suggestions For Reading Professional Journals
General
Editorials
1. Preview, title, introduction (paragraph 1). Summary (last paragraph)—quickly.
2. Read: if further interested, read first sentence of the second paragraph for topic, then skip-phrase through paragraph, if it appears worthwhile. Handle remaining paragraphs the same way.
3. Review: look away from the material, verbalize the points of concern to you. Check back if necessary.
Announcements
1. Skim: for topic, if interesting to you
2. Check: for date, place, personnel
Special Articles (Historical), Etc
1. Skim: titles, for each of possible interest.
2. Check: introduction and summary. If it’s any worth to you.
3. ….handle balance of selections as with editorials.
Reviews
1. Check: bibliographic note at beginning; if of possible interest.
2. Skim: concluding paragraphs or sentences for reviewer’s summary. If you wish to know more..
3. Read: rest of review of skim-phrasing.
‘Specific’ (Reports of studies and investigations)
General Approach
1. Evaluate titles: Decide which you wish to know more about; for each.
2. Skim introduction, illustration, summary.
3. If and to the extent necessary for you, read and review article.
Evaluating a study in detail
1. What is the problem? What actually was studied may be somewhat different than the title indicates……restate the problem in your own words, if possible,
2. What type of study is it?
a. Exploratory
b. Survey
c. Descriptive
d. Experimental
3. Developing Listening Skills
Listening is the first input skill of language. In this age of media and muzak in every public place, the adolescent is a very poor listener. He is used to bring bombarded with noise, color, and fast movement and has developed the ability to isolate himself from peripheral sounds. Many of these young people have developed bad listening habits, and can tune out whatever does not ‘grab’ them. They have to be taught listening habits. A suggestion follows.
Listening
Ten bad listening habits
Bad (how to tune out)
1. calling subject uninteresting and tuning out.
2. criticizing delivery (poor organization, etc.)
3. getting overstimulated and tuning out.
4. listening only for FACTS (utterly inefficient), WORST listeners do this and think its good.
5. outlining everything (rigid)
6. faking attention.
7. tolerating or creating distractions (can’t hear speaker, etc.).
8. avoiding difficult material.
9. letting ‘emotion words’ throw you off.
10. wasting ‘the differential between speech and though speed.’ Lecturer 100 wpm; average thinker 400 wpm; Mind wanders while speaker catches up; You are tuned ‘cut for 50 in for 10’.
Good (how to overcome)
1. Can I use it? Sift, screen, bear down on subject.
2. Dig out what’s needed. Responsibility on you, not lecturer.
3. ‘Withhold evaluation until comprehension is complete’, ie. hear him out before judging.
4. Listen for ideas and concepts. Facts then arrange themselves. Helps retention.
5. Mostly you can’t. Use flexible techniques. (list of ideas and facts a good technique)—precise, abstract, etc.
6. Concentrate (who are you kidding?)
7. Eliminate them. Be aggressive about it.
8. Try it.
9. Be aware some words throw you. Don’t be thrown. Tolerate.
10. Use the time—gap to concentrate.
Three ingredients of good concentration:
- Anticipate what he’s going to say and then compare what he said with what you thought was coming.
- Identify his evidence. (This is where facts come in)
4. Lecture Notes
Taking good lecture notes is an essential component of learning a subject. However, so often this important skill is thought to be learnt by osmosis and not be teaching. A suggested plan for lecture note taking follows.
Taking Lecture Notes
There are many reasons for taking lecture notes.
- Making yourself take notes forces you to listen carefully and test your understanding of the material.
- When you are reviewing, notes provide a gauge to what is important in the text.
- Personal notes are usually easier to remember than the text.
- The writing down of important points helps you to remember them even before you have studied the material formally.
Instructors usually give clues to what is important to take down. Some of the more common clues are:
- Material written on the blackboard
- Repetition
- Emphasis
1. Emphasis can be judged by tone of voice and gesture.
2. Emphasis can be judged by amount of time instructor spends on points and number of examples he uses.
- Work signals (eg. “There are two points of view on…. The third reason is…..In conclusion…)
- Summaries given at end of class.
- Reviews given at beginning of class.
Each student should develop his own method of taking notes, but most students find the following suggestions helpful:
- Make your notes brief.
1. Never use a sentence where you can use a phrase. Never use a phrase where you can a use a word.
2. Use abbreviations and symbols.
- Put most notes in your own words. However, the following should be noted exactly.
1. Formulas
2. Definitions
3. Specific facts
- Use outline form and/or a numbering system. Indentation helps you distinguish major from minor points.
- If you miss a statement, write key words, skip a few spaces, and get the information later.
- Don’t try to use every space on the page. Leave room for coordinating your notes with text after the lecture. (You may want to list key terms in the margin or to make a summary of the contents of the page).
- Date your notes. Perhaps number the pages.
4. Developing Competence In Writing And Speaking
Discussion is as basic to good writing as it is to good oral language activities. Speaking is one of the outputs of language, the other is writing. Through talk students can develop the easy use of technical words and the fluency of expression that supports fluent writing:
- Talk gets ideas flowing
- Talk familiarizes vocabulary
- Talk provides opportunity to set out sentence patterns of constructions
- Talk promotes organization for clarity
- Talk establishes cause—effect relationship
- Talk organizes sequence of events
Quality of expression is tied to quality of input. Just as children pattern their oral language on what they hear during oral exchanges so students will absorb from their listening and reading the pattern of technical language. Academics should draw students attention to clear well written technical language.
The conventions of writing develop as students write and are interested in others reading their product. The conventions of handwriting, spelling and punctuation help to facilitate communication with the reader. Proof-reading is an essential component of good writing. Spelling of technical jargon words has to be learned, always remembering that spelling is a visual skill not an oral one (unless to confound small children).
The look of a word and the practice of writing it is important. Reading and spelling are often confused and there is concern for the ‘good’ reader who is a ‘bad’ speller. Reading is recognition while spelling is selection, e.g., pain, to spell the sound could be ai, ae, a….e, ei or ay.
Some of the points to avoid in technical writing can be itemized as follows:
1. Ambiguity: make sure writing has one meaning only.
2. Monotony of sentences: vary the length and construction of sentences.
3. Pretentious writing: do not use exaggerated expressions when simpler words will do.
4. Cliches, colloquialism, slang: look for fresher turns of phrase.
5. Unfamiliar words: do not use words if you do not know their meaning.
6. Circumlocution: be concise and to the point.
7. Unnecessary repetition: do not repeat the same word or phrase too soon. Read each paragraph as it is finished and any repetition will be noticed immediately.
1. What is literacy?
What is literacy and why do we need a perspective on it? The term has been the subject of much debate in recent years but rarely is a definition attempted. First, literacy does not just mean reading. The Concise Oxford Dictionary defines literacy as ‘the ability to read and write’. If we add to this the ability to speak our native language concisely and fluently and to listen effectively to others speaking it, we come nearer to the broader meaning of literacy; the mastery of our native language in all its aspects, as a means of communication. The mastery of these four interrelated skills, reading, writing, speaking and listening, is a long term process and an extensive program of training at all ages is necessary.
2. How to read?
Reading a text chapter once is not enough. Most students retain less than 25% of a chapter’s contents after one reading. A better method is to spend a few minutes skimming through the chapter, noting topic headings, charts and italics and reading the summary. This will give an overview of the contents and prepare for a more thorough reading. Next, turn the topic headings into questions and read for the answers. Test by trying to recall the answers. Selectively review by re-reading these sections which are not clear. If underlining is to be done, it should be done at this stage and not during the first reading of the chapter. The final step is the brief outline of the chapter.
Reading Professional Journal
Students should have the foundations of continuing education fostered through the reading of professional journals. But professional journals are voluminous and many, and a word by word reading of the relevant seeming articles is tedious and time wasting. A suggested plan to attack for keeping abreast with current papers follows:
Suggestions For Reading Professional Journals
General
Editorials
1. Preview, title, introduction (paragraph 1). Summary (last paragraph)—quickly.
2. Read: if further interested, read first sentence of the second paragraph for topic, then skip-phrase through paragraph, if it appears worthwhile. Handle remaining paragraphs the same way.
3. Review: look away from the material, verbalize the points of concern to you. Check back if necessary.
Announcements
1. Skim: for topic, if interesting to you
2. Check: for date, place, personnel
Special Articles (Historical), Etc
1. Skim: titles, for each of possible interest.
2. Check: introduction and summary. If it’s any worth to you.
3. ….handle balance of selections as with editorials.
Reviews
1. Check: bibliographic note at beginning; if of possible interest.
2. Skim: concluding paragraphs or sentences for reviewer’s summary. If you wish to know more..
3. Read: rest of review of skim-phrasing.
‘Specific’ (Reports of studies and investigations)
General Approach
1. Evaluate titles: Decide which you wish to know more about; for each.
2. Skim introduction, illustration, summary.
3. If and to the extent necessary for you, read and review article.
Evaluating a study in detail
1. What is the problem? What actually was studied may be somewhat different than the title indicates……restate the problem in your own words, if possible,
2. What type of study is it?
a. Exploratory
b. Survey
c. Descriptive
d. Experimental
3. Developing Listening Skills
Listening is the first input skill of language. In this age of media and muzak in every public place, the adolescent is a very poor listener. He is used to bring bombarded with noise, color, and fast movement and has developed the ability to isolate himself from peripheral sounds. Many of these young people have developed bad listening habits, and can tune out whatever does not ‘grab’ them. They have to be taught listening habits. A suggestion follows.
Listening
Ten bad listening habits
Bad (how to tune out)
1. calling subject uninteresting and tuning out.
2. criticizing delivery (poor organization, etc.)
3. getting overstimulated and tuning out.
4. listening only for FACTS (utterly inefficient), WORST listeners do this and think its good.
5. outlining everything (rigid)
6. faking attention.
7. tolerating or creating distractions (can’t hear speaker, etc.).
8. avoiding difficult material.
9. letting ‘emotion words’ throw you off.
10. wasting ‘the differential between speech and though speed.’ Lecturer 100 wpm; average thinker 400 wpm; Mind wanders while speaker catches up; You are tuned ‘cut for 50 in for 10’.
Good (how to overcome)
1. Can I use it? Sift, screen, bear down on subject.
2. Dig out what’s needed. Responsibility on you, not lecturer.
3. ‘Withhold evaluation until comprehension is complete’, ie. hear him out before judging.
4. Listen for ideas and concepts. Facts then arrange themselves. Helps retention.
5. Mostly you can’t. Use flexible techniques. (list of ideas and facts a good technique)—precise, abstract, etc.
6. Concentrate (who are you kidding?)
7. Eliminate them. Be aggressive about it.
8. Try it.
9. Be aware some words throw you. Don’t be thrown. Tolerate.
10. Use the time—gap to concentrate.
Three ingredients of good concentration:
- Anticipate what he’s going to say and then compare what he said with what you thought was coming.
- Identify his evidence. (This is where facts come in)
4. Lecture Notes
Taking good lecture notes is an essential component of learning a subject. However, so often this important skill is thought to be learnt by osmosis and not be teaching. A suggested plan for lecture note taking follows.
Taking Lecture Notes
There are many reasons for taking lecture notes.
- Making yourself take notes forces you to listen carefully and test your understanding of the material.
- When you are reviewing, notes provide a gauge to what is important in the text.
- Personal notes are usually easier to remember than the text.
- The writing down of important points helps you to remember them even before you have studied the material formally.
Instructors usually give clues to what is important to take down. Some of the more common clues are:
- Material written on the blackboard
- Repetition
- Emphasis
1. Emphasis can be judged by tone of voice and gesture.
2. Emphasis can be judged by amount of time instructor spends on points and number of examples he uses.
- Work signals (eg. “There are two points of view on…. The third reason is…..In conclusion…)
- Summaries given at end of class.
- Reviews given at beginning of class.
Each student should develop his own method of taking notes, but most students find the following suggestions helpful:
- Make your notes brief.
1. Never use a sentence where you can use a phrase. Never use a phrase where you can a use a word.
2. Use abbreviations and symbols.
- Put most notes in your own words. However, the following should be noted exactly.
1. Formulas
2. Definitions
3. Specific facts
- Use outline form and/or a numbering system. Indentation helps you distinguish major from minor points.
- If you miss a statement, write key words, skip a few spaces, and get the information later.
- Don’t try to use every space on the page. Leave room for coordinating your notes with text after the lecture. (You may want to list key terms in the margin or to make a summary of the contents of the page).
- Date your notes. Perhaps number the pages.
4. Developing Competence In Writing And Speaking
Discussion is as basic to good writing as it is to good oral language activities. Speaking is one of the outputs of language, the other is writing. Through talk students can develop the easy use of technical words and the fluency of expression that supports fluent writing:
- Talk gets ideas flowing
- Talk familiarizes vocabulary
- Talk provides opportunity to set out sentence patterns of constructions
- Talk promotes organization for clarity
- Talk establishes cause—effect relationship
- Talk organizes sequence of events
Quality of expression is tied to quality of input. Just as children pattern their oral language on what they hear during oral exchanges so students will absorb from their listening and reading the pattern of technical language. Academics should draw students attention to clear well written technical language.
The conventions of writing develop as students write and are interested in others reading their product. The conventions of handwriting, spelling and punctuation help to facilitate communication with the reader. Proof-reading is an essential component of good writing. Spelling of technical jargon words has to be learned, always remembering that spelling is a visual skill not an oral one (unless to confound small children).
The look of a word and the practice of writing it is important. Reading and spelling are often confused and there is concern for the ‘good’ reader who is a ‘bad’ speller. Reading is recognition while spelling is selection, e.g., pain, to spell the sound could be ai, ae, a….e, ei or ay.
Some of the points to avoid in technical writing can be itemized as follows:
1. Ambiguity: make sure writing has one meaning only.
2. Monotony of sentences: vary the length and construction of sentences.
3. Pretentious writing: do not use exaggerated expressions when simpler words will do.
4. Cliches, colloquialism, slang: look for fresher turns of phrase.
5. Unfamiliar words: do not use words if you do not know their meaning.
6. Circumlocution: be concise and to the point.
7. Unnecessary repetition: do not repeat the same word or phrase too soon. Read each paragraph as it is finished and any repetition will be noticed immediately.
Cutting Cubic Zirconia
(via Gem Cutter, March 1982) Wahroongai News writes:
We have been asked to furnish information about cutting cubic zirconia. As is usual in the faceting field, various cutters develop their own techniques but a little research brought the following results:
The recommended proportions appear to be 1/3 crown and 2/3 pavilion with the table 55% of the width. For cutting round brilliants, one cutter suggest crown mains 35º and pavilion 41º whilst another quotes 34½º and 40¾º respectively. The critical angle is specified as 28º. Yet another experienced cutter stated that the Barion cut, originally developed for diamond cutting, is quite ‘spectacular’ in cubic zirconia.
‘Make haste slowly’ is the opinion of some facetors; it is necessary to proceed by degrees. First use 600 micron diamond on a copper lap with water; followed by 1200 micron on copper with oil; then 3000 micron on copper with oil. Don’t overdo the diamond—a little goes a long way with cubic zirconia.
A smooth lap is needed—a well worn one seems to work best. And—avoid contamination at all costs! Another opinion was that one needed to use only a medium diamond disc (260 grit) and then proceed to polish. All agreed that a fine satin finish at this stage meant less polishing and that the polishing should be done with Linde A on a tin lap, well scored, and at a moderately slow speed. The only alternatives suggested were ¼ micron diamond dust on a zinc or a ceramic lap.
Incidentally, it is interesting to note that cubic zirconia was originally produced for scientific and technological purposes and its use in the gem and jewelry trade was merely a side issue. Also, the colors in which is now produced are derived by purposely adding, usually a minute quantities, some impurity (called ‘dopant’) and that many of these additives are rare-earths.
Dopant used: Cerium; Color produced: Yellow-orange-red
Dopant used: Chromium; Color produced: Olive
Dopant used: Cobalt; Color produced: Lilac
Dopant used: Copper; Color produced: Yellow
Dopant used: Erbium; Color produced: Pink
Dopant used: Europium; Color produced: Pink
Dopant used: Holmium; Color produced: Pink
Dopant used: Iron; Color produced: Yellow
Dopant used: Manganese; Color produced: Brown-violet
Dopant used: Neodymium; Color produced: Lilac
Dopant used: Nickel; Color produced: Yellow-brown
Dopant used: Praseodymium; Color produced: Amber
Dopant used: Thulium; Color produced: Green
Dopant used: Titanium; Color produced: Yellow-brown
Dopant used: Vanadium; Color produced: Green
We have been asked to furnish information about cutting cubic zirconia. As is usual in the faceting field, various cutters develop their own techniques but a little research brought the following results:
The recommended proportions appear to be 1/3 crown and 2/3 pavilion with the table 55% of the width. For cutting round brilliants, one cutter suggest crown mains 35º and pavilion 41º whilst another quotes 34½º and 40¾º respectively. The critical angle is specified as 28º. Yet another experienced cutter stated that the Barion cut, originally developed for diamond cutting, is quite ‘spectacular’ in cubic zirconia.
‘Make haste slowly’ is the opinion of some facetors; it is necessary to proceed by degrees. First use 600 micron diamond on a copper lap with water; followed by 1200 micron on copper with oil; then 3000 micron on copper with oil. Don’t overdo the diamond—a little goes a long way with cubic zirconia.
A smooth lap is needed—a well worn one seems to work best. And—avoid contamination at all costs! Another opinion was that one needed to use only a medium diamond disc (260 grit) and then proceed to polish. All agreed that a fine satin finish at this stage meant less polishing and that the polishing should be done with Linde A on a tin lap, well scored, and at a moderately slow speed. The only alternatives suggested were ¼ micron diamond dust on a zinc or a ceramic lap.
Incidentally, it is interesting to note that cubic zirconia was originally produced for scientific and technological purposes and its use in the gem and jewelry trade was merely a side issue. Also, the colors in which is now produced are derived by purposely adding, usually a minute quantities, some impurity (called ‘dopant’) and that many of these additives are rare-earths.
Dopant used: Cerium; Color produced: Yellow-orange-red
Dopant used: Chromium; Color produced: Olive
Dopant used: Cobalt; Color produced: Lilac
Dopant used: Copper; Color produced: Yellow
Dopant used: Erbium; Color produced: Pink
Dopant used: Europium; Color produced: Pink
Dopant used: Holmium; Color produced: Pink
Dopant used: Iron; Color produced: Yellow
Dopant used: Manganese; Color produced: Brown-violet
Dopant used: Neodymium; Color produced: Lilac
Dopant used: Nickel; Color produced: Yellow-brown
Dopant used: Praseodymium; Color produced: Amber
Dopant used: Thulium; Color produced: Green
Dopant used: Titanium; Color produced: Yellow-brown
Dopant used: Vanadium; Color produced: Green
Old Chinese Snuff Bottles
By Henry C Hitt
Charles E Tuttle Company
1978 ISBN 0-8048-1220-9
Charles E Tuttle Company writes:
Among collectors of Chinese snuff bottles, the name of the late Henry C Hitt has long commanded respect, not only as that of an ardent fellow collector but also as that of the author of the first book on the subject in any language—a work that had the great value of arousing collectors everywhere, even in China. This book, which appeared in first and second editions and was followed by a supplement, has in itself become a collector’s item. Until now, however, it has been practically impossible to obtain, for it was a handmade book produced by lithographic methods, and it had little hope of ever being reprinted. The present edition remedies this lack by bringing together facsimile copies of the expanded second edition (1945) and the supplement and thereby making available to a much wider audience Mr Hitt’s invaluable contribution to the fascinating subject of snuff bottle collecting.
In this introduction to the second edition, Mr Hitt wrote: “There is an almost total lack of literature on Chinese snuff bottles. This is, as far as is known, the only book on the subject, and there have been only a few magazine articles.” To be sure, since the appearance of the book in 1945 there have been numerous other books and articles on the subject, but this by no means diminishes the value of his pioneering work or the honor he achieved by being one of the first to share his knowledge with other enthusiastic collectors. And it is exactly for the benefit of these enthusiastic collectors that this new facsimile edition is being offered.
Charles E Tuttle Company
1978 ISBN 0-8048-1220-9
Charles E Tuttle Company writes:
Among collectors of Chinese snuff bottles, the name of the late Henry C Hitt has long commanded respect, not only as that of an ardent fellow collector but also as that of the author of the first book on the subject in any language—a work that had the great value of arousing collectors everywhere, even in China. This book, which appeared in first and second editions and was followed by a supplement, has in itself become a collector’s item. Until now, however, it has been practically impossible to obtain, for it was a handmade book produced by lithographic methods, and it had little hope of ever being reprinted. The present edition remedies this lack by bringing together facsimile copies of the expanded second edition (1945) and the supplement and thereby making available to a much wider audience Mr Hitt’s invaluable contribution to the fascinating subject of snuff bottle collecting.
In this introduction to the second edition, Mr Hitt wrote: “There is an almost total lack of literature on Chinese snuff bottles. This is, as far as is known, the only book on the subject, and there have been only a few magazine articles.” To be sure, since the appearance of the book in 1945 there have been numerous other books and articles on the subject, but this by no means diminishes the value of his pioneering work or the honor he achieved by being one of the first to share his knowledge with other enthusiastic collectors. And it is exactly for the benefit of these enthusiastic collectors that this new facsimile edition is being offered.
Monday, March 19, 2007
Weakly Radioactive Spinel Triplets
(via ICA Early Warning Flash, No.23, November 1989) Kurt Nassau writes:
A New York gemstone merchant accidentally placed a parcel of spinel triplets near his Geiger counter and was surprised when radioactivity was detected. Some of the stones involved were examined by me. They are yellow green, apparently intended to imitate peridot, and are said to be manufactured in Europe. Analysis shows that they consist of two layers of colorless spinel cemented together with a green lead and uranium-containing glass. The uranium provides both the color and the radioactivity. A single stone counts only just double the background on a small ‘monitor 4’ Geiger counter; accordingly the amount of radiation produced from an individual stone is not easy to detect and probably harmless. Nevertheless, significant activity is given off by a parcel containing many such stones. Gemologists and dealers should be aware of this situation.
A New York gemstone merchant accidentally placed a parcel of spinel triplets near his Geiger counter and was surprised when radioactivity was detected. Some of the stones involved were examined by me. They are yellow green, apparently intended to imitate peridot, and are said to be manufactured in Europe. Analysis shows that they consist of two layers of colorless spinel cemented together with a green lead and uranium-containing glass. The uranium provides both the color and the radioactivity. A single stone counts only just double the background on a small ‘monitor 4’ Geiger counter; accordingly the amount of radiation produced from an individual stone is not easy to detect and probably harmless. Nevertheless, significant activity is given off by a parcel containing many such stones. Gemologists and dealers should be aware of this situation.
Sideways
Memorable quote (s) from the movie:
Maya (Virginia Madsen): You know, can I ask you a personal question, Miles?
Miles Raymond (Paul Giamatti): Sure.
Maya (Virginia Madsen: Why are you so in to Pinot? I mean, it's like a thing with you.
Miles Raymond (Paul Giamatti): Uh, I don't know, I don't know. Um, it's a hard grape to grow, as you know. Right? It's uh, it's thin-skinned, temperamental, ripens early. It's, you know, it's not a survivor like Cabernet, which can just grow anywhere and uh, thrive even when it's neglected. No, Pinot needs constant care and attention. You know? And in fact it can only grow in these really specific, little, tucked away corners of the world. And, and only the most patient and nurturing of growers can do it, really. Only somebody who really takes the time to understand Pinot's potential can then coax it into its fullest expression. Then, I mean, oh its flavors, they're just the most haunting and brilliant and thrilling and subtle and... ancient on the planet.
Maya (Virginia Madsen): You know, can I ask you a personal question, Miles?
Miles Raymond (Paul Giamatti): Sure.
Maya (Virginia Madsen: Why are you so in to Pinot? I mean, it's like a thing with you.
Miles Raymond (Paul Giamatti): Uh, I don't know, I don't know. Um, it's a hard grape to grow, as you know. Right? It's uh, it's thin-skinned, temperamental, ripens early. It's, you know, it's not a survivor like Cabernet, which can just grow anywhere and uh, thrive even when it's neglected. No, Pinot needs constant care and attention. You know? And in fact it can only grow in these really specific, little, tucked away corners of the world. And, and only the most patient and nurturing of growers can do it, really. Only somebody who really takes the time to understand Pinot's potential can then coax it into its fullest expression. Then, I mean, oh its flavors, they're just the most haunting and brilliant and thrilling and subtle and... ancient on the planet.
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