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.
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