By Robert Webster
Revised by B.W.Andersen
Butterworths
1989 (4th Edition), Reprinted 1987, 1989
ISBN 0-408-01148-3
Butterworths writes:
Since it was first published in 1962, Gems: Their Sources, Descriptions and Identification has become firmly established as the most comprehensive and authoritative account of gemstones available in the English language.
The period since publication of the third edition, in 1975, has seen numerous changes of far-reaching consequence for the science of gemology. A large proportion of these changes has been brought about as a direct consequence of the appearance in quantity of cubic zirconia, an extremely successful stimulant of diamond. Thus, a full description of cubic zirconia and the associated new test instruments has been a foremost concern for Basil Anderson in this revision.
There have been other additions to the range of synthetic gemstones, most importantly synthetic opal, and recent advances in the techniques for altering the color of gemstones. These are described and discussed in detail in this new edition, along with several new gem minerals and the current procedures for diamond grading.
Although primarily aimed at the professional jeweler and student gemologist, Gems is also an essential item in the library of the collector and the layman who is interested in precious stones.
About the author
Robert Webster is the author of two other books: Practical Gemmology and The Gemmologist’s Compendium
Friday, February 02, 2007
Thursday, February 01, 2007
How To Identify The Source Of African Ivory
Using sophisticated statistical analysis of genetic data the scientists are applying new DNA techniques extracted from African elephant dung and skin samples to identify the origin of illegally poached ivory with remarkable accuracy.
More info @ http://www.abc.net.au/science/news/stories/s1208970.htm
More info @ http://www.abc.net.au/science/news/stories/s1208970.htm
The Pink Panther Movie
Memorable quote (s) from the movie:
Gem dealer 1: As in every stone of this size, there is a flaw.
Sultan: A flaw?
Gem dealer 2: The slightest flaw, your excellency.
Gem dealer 1: If you look deep into the stone, you will perceive the tiniest discoloration. It resembles an animal.
Sultan: An animal?
Gem dealer 1: A little panther.
Sultan: Yes! A pink panther. Come here, Dala. A gift to your father from his grateful people. Some day it will be yours. The most fabulous diamond in all the world. Come closer.
Gem dealer 1: As in every stone of this size, there is a flaw.
Sultan: A flaw?
Gem dealer 2: The slightest flaw, your excellency.
Gem dealer 1: If you look deep into the stone, you will perceive the tiniest discoloration. It resembles an animal.
Sultan: An animal?
Gem dealer 1: A little panther.
Sultan: Yes! A pink panther. Come here, Dala. A gift to your father from his grateful people. Some day it will be yours. The most fabulous diamond in all the world. Come closer.
The Federal Trade Commission’s Guide for the Jewelry, Precious Metals and Pewter Industries
FTC writes:
23.6 Misrepresentation as to silver content.
(a) It is unfair or deceptive to misrepresent that an industry product contains silver, or to misrepresent an industry product as having a silver content, plating, electroplating, or coating.
(b) It is unfair or deceptive to mark, describe, or otherwise represent all or part of an industry product as "silver," "solid silver," "Sterling Silver," "Sterling," or the abbreviation "Ster." unless it is at least 925/1,000ths pure silver.
(c) It is unfair or deceptive to mark, describe, or otherwise represent all or part of an industry product as "coin" or "coin silver" unless it is at least 900/1,000ths pure silver.
(d) It is unfair or deceptive to mark, describe, or otherwise represent all or part of an industry product as being plated or coated with silver unless all significant surfaces of the product or part contain a plating or coating of silver that is of substantial thickness.8
(e) The provisions of this section relating to markings and descriptions of industry products and parts thereof are subject to the applicable tolerances of the National Stamping Act or any amendment thereof.9
Note 1 to 23.6: The National Stamping Act provides that silverplated articles shall not "be stamped, branded, engraved or imprinted with the word ‘sterling’ or the word ‘coin,’ either alone or in conjunction with other words or marks." 15 U.S.C. 297(a).
Note 2 to 23.6: Exemptions recognized in the assay of silver industry products are listed in the appendix.
More info @ http://www.ftc.gov/bcp/guides/jewel-gd.htm
23.6 Misrepresentation as to silver content.
(a) It is unfair or deceptive to misrepresent that an industry product contains silver, or to misrepresent an industry product as having a silver content, plating, electroplating, or coating.
(b) It is unfair or deceptive to mark, describe, or otherwise represent all or part of an industry product as "silver," "solid silver," "Sterling Silver," "Sterling," or the abbreviation "Ster." unless it is at least 925/1,000ths pure silver.
(c) It is unfair or deceptive to mark, describe, or otherwise represent all or part of an industry product as "coin" or "coin silver" unless it is at least 900/1,000ths pure silver.
(d) It is unfair or deceptive to mark, describe, or otherwise represent all or part of an industry product as being plated or coated with silver unless all significant surfaces of the product or part contain a plating or coating of silver that is of substantial thickness.8
(e) The provisions of this section relating to markings and descriptions of industry products and parts thereof are subject to the applicable tolerances of the National Stamping Act or any amendment thereof.9
Note 1 to 23.6: The National Stamping Act provides that silverplated articles shall not "be stamped, branded, engraved or imprinted with the word ‘sterling’ or the word ‘coin,’ either alone or in conjunction with other words or marks." 15 U.S.C. 297(a).
Note 2 to 23.6: Exemptions recognized in the assay of silver industry products are listed in the appendix.
More info @ http://www.ftc.gov/bcp/guides/jewel-gd.htm
Gemstone Enhancement
By Kurt Nassau
Butterworths
1984 ISBN 0-408-01447-4
Butterworths writes:
In recent years there has been a tremendous expansion in the use of treatments to enhance the color and appearance of gemstones. This includes various types of irradiation and heat treatments, colorless impregnations, bleaching, dyeing, diffusion, and other processes. Some of these processes date back at least two thousand years, others are of quite recent origin.
Gemstone Enhancement begins with a short account of the history of gemstone treatments, followed by three chapters giving an outline of the technologies of irradiation, heat, and other enhancement processes. A chapter deals with the techniques used in the identification of treated gemstones and the question of disclosure. The core of the book is an extended alphabetical listing of all the gemstones and related materials which have been applied to each. This includes details of the processes used where known, methods of identification, and references to published descriptions. Additional technical details and scientific explanations are given in Appendixes for the interest of the reader.
The book is written for the gemologist to simplify his or her work: by knowing the details of the possible treatment techniques, the treatments that have been applied to the gemstone under study can be more readily recognized. Collectors, dealers, jewelers, appraisers, pawnbrokers and others interested in gemstones will also gain added insight from knowing the range of possible treatments. All the fundamental concepts are covered, so only a general knowledge of gems is required of the reader.
About the author
Kurt Nassau is the author of Gems Made By Man and The Physics and Chemistry Of Color.
Butterworths
1984 ISBN 0-408-01447-4
Butterworths writes:
In recent years there has been a tremendous expansion in the use of treatments to enhance the color and appearance of gemstones. This includes various types of irradiation and heat treatments, colorless impregnations, bleaching, dyeing, diffusion, and other processes. Some of these processes date back at least two thousand years, others are of quite recent origin.
Gemstone Enhancement begins with a short account of the history of gemstone treatments, followed by three chapters giving an outline of the technologies of irradiation, heat, and other enhancement processes. A chapter deals with the techniques used in the identification of treated gemstones and the question of disclosure. The core of the book is an extended alphabetical listing of all the gemstones and related materials which have been applied to each. This includes details of the processes used where known, methods of identification, and references to published descriptions. Additional technical details and scientific explanations are given in Appendixes for the interest of the reader.
The book is written for the gemologist to simplify his or her work: by knowing the details of the possible treatment techniques, the treatments that have been applied to the gemstone under study can be more readily recognized. Collectors, dealers, jewelers, appraisers, pawnbrokers and others interested in gemstones will also gain added insight from knowing the range of possible treatments. All the fundamental concepts are covered, so only a general knowledge of gems is required of the reader.
About the author
Kurt Nassau is the author of Gems Made By Man and The Physics and Chemistry Of Color.
Wednesday, January 31, 2007
Some Like It Hot
Here is a memorable quote from the movie:
Sugar(Marlyn Monroe): Real diamonds! They must be worth their weight in gold!
Sugar(Marlyn Monroe): Real diamonds! They must be worth their weight in gold!
Gem Poetry
Pablo Neruda writes:
When you touch the topaz
the topaz touches you;
Awakening the mellow fire
as the wine in the grape
awakens.
Long before it is born, the clear wine
within the stone
gropes for circulation, asks for words,
delivers its mysterious nutriment,
shares the kiss of the human skin
the contact serene
of stone and human being
enkindling a swift corolla
that later returns to be what it was before:
flesh and stone: entities enemies.
When you touch the topaz
the topaz touches you;
Awakening the mellow fire
as the wine in the grape
awakens.
Long before it is born, the clear wine
within the stone
gropes for circulation, asks for words,
delivers its mysterious nutriment,
shares the kiss of the human skin
the contact serene
of stone and human being
enkindling a swift corolla
that later returns to be what it was before:
flesh and stone: entities enemies.
The Federal Trade Commission’s Guide for the Jewelry, Precious Metals and Pewter Industries
FTC writes:
23.5 Misuse of the word "vermeil."
(a) It is unfair or deceptive to represent, directly or by implication, that an industry product is "vermeil" if such mark or description misrepresents the product's true composition.
(b) An industry product may be described or marked as "vermeil" if it consists of a base of sterling silver coated or plated on all significant surfaces with gold, or gold alloy of not less than 10 karat fineness, that is of substantial thickness(7) and a minimum thickness throughout equivalent to two and one half (2 1/2) microns (or approximately 100/1,000,000ths of an inch) of fine gold.
Note 1 to 23.5: It is unfair or deceptive to use the term "vermeil" to describe a product in which the sterling silver has been covered with a base metal (such as nickel) plated with gold unless there is a disclosure that the sterling silver is covered with a base metal that is plated with gold.
Note 2 to 23.5: Exemptions recognized in the assay of gold filled, gold overlay, and rolled gold plate industry products are listed in the appendix.
More info @ http://www.ftc.gov/bcp/guides/jewel-gd.htm
23.5 Misuse of the word "vermeil."
(a) It is unfair or deceptive to represent, directly or by implication, that an industry product is "vermeil" if such mark or description misrepresents the product's true composition.
(b) An industry product may be described or marked as "vermeil" if it consists of a base of sterling silver coated or plated on all significant surfaces with gold, or gold alloy of not less than 10 karat fineness, that is of substantial thickness(7) and a minimum thickness throughout equivalent to two and one half (2 1/2) microns (or approximately 100/1,000,000ths of an inch) of fine gold.
Note 1 to 23.5: It is unfair or deceptive to use the term "vermeil" to describe a product in which the sterling silver has been covered with a base metal (such as nickel) plated with gold unless there is a disclosure that the sterling silver is covered with a base metal that is plated with gold.
Note 2 to 23.5: Exemptions recognized in the assay of gold filled, gold overlay, and rolled gold plate industry products are listed in the appendix.
More info @ http://www.ftc.gov/bcp/guides/jewel-gd.htm
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