FTC writes:
23.3 Misuse of the terms "hand-made," "hand-polished," etc.
(a) It is unfair or deceptive to represent, directly or by implication, that any industry product is hand-made or hand-wrought unless the entire shaping and forming of such product from raw materials and its finishing and decoration were accomplished by hand labor and manually-controlled methods which permit the maker to control and vary the construction, shape, design, and finish of each part of each individual product.
Note to paragraph (a): As used herein, "raw materials" include bulk sheet, strip, wire, and similar items that have not been cut, shaped, or formed into jewelry parts, semi-finished parts, or blanks.
(b) It is unfair or deceptive to represent, directly or by implication, that any industry product is hand-forged, hand-engraved, hand-finished, or hand-polished, or has been otherwise hand-processed, unless the operation described was accomplished by hand labor and manually-controlled methods which permit the maker to control and vary the type, amount, and effect of such operation on each part of each individual product.
More info @ http://www.ftc.gov/bcp/guides/jewel-gd.htm
Sunday, January 28, 2007
Color Encyclopedia Of Gemstones
By Joel E Arem
Van Nostrand Reinhold Ltd
1977 ISBN 0-442-20333-0
Van Nostrand Reinhold writes:
This important new encyclopedia is a milestone in lapidary publishing. It is the first reference source to present data on every known species and varieties of gemstone. Furthermore, its rich selection of color photographs shows more species than have ever before appeared in one volume.
You can easily find the data you need to identify any gemstone. Alphabetical listing arranges gems according to mineral species. There is also a complete cross index of familiar gem names. Information on each gem includes chemical formula, crystal structure, colors, luster, hardness, density, cleavage, optics, spectral data, luminescence, and sizes. Over 220 mineral species are covered, and the color plates illustrate more than 185 of these—including all known color varieties of each species. For as many as 100 of the rarer species a color photograph appears for the first time in print.
Arem’s transparencies represent today’s most sophisticated techniques for gem photography. Resulting from his own three-year effort, they show the exact color of faceted gemstones while displaying to best advantage the cut and brilliance derived from the cutting. At the same time ‘hot spots’ or specular reflections from individual facets are avoided. The photos achieve naturalistic solidity and dimension, in many cases clearly revealing the degree of birefringence in a gem, as well as any inclusions.
Some of the data provided have never been published before, such as the dispersion values for 15 gem materials. These values are calculated from material scattered throughout mineralogical literature, and reworked to make them useful for gemologists.
Of practical interest to gem cutters is a special graph relating critical angle and refractive index. Other books list critical angles for various gems, but, because of the wide range in optical properties in certain gem species, these numbers are not always valid. The graph included here makes it possible to determine the exact critical angle to use for the specific material to be cut.
With growing interest in investment potential of gemstones, the lay public can also consult this versatile reference for information or photographs before making a decision to purchase. Collectors of gems, especially connoisseurs, will view the unique color plates of many exotic gem species with special pleasure.
About the author
Joel E Arem was awarded PhD in mineralogy at Harvard in 1970. His research specialties are crystal growth and X-ray crystal structure analysis. Dr Arem is the author of three previously published titles: Rocks and Minerals, Gems and Jewelry, and Man-made Crystals.
Van Nostrand Reinhold Ltd
1977 ISBN 0-442-20333-0
Van Nostrand Reinhold writes:
This important new encyclopedia is a milestone in lapidary publishing. It is the first reference source to present data on every known species and varieties of gemstone. Furthermore, its rich selection of color photographs shows more species than have ever before appeared in one volume.
You can easily find the data you need to identify any gemstone. Alphabetical listing arranges gems according to mineral species. There is also a complete cross index of familiar gem names. Information on each gem includes chemical formula, crystal structure, colors, luster, hardness, density, cleavage, optics, spectral data, luminescence, and sizes. Over 220 mineral species are covered, and the color plates illustrate more than 185 of these—including all known color varieties of each species. For as many as 100 of the rarer species a color photograph appears for the first time in print.
Arem’s transparencies represent today’s most sophisticated techniques for gem photography. Resulting from his own three-year effort, they show the exact color of faceted gemstones while displaying to best advantage the cut and brilliance derived from the cutting. At the same time ‘hot spots’ or specular reflections from individual facets are avoided. The photos achieve naturalistic solidity and dimension, in many cases clearly revealing the degree of birefringence in a gem, as well as any inclusions.
Some of the data provided have never been published before, such as the dispersion values for 15 gem materials. These values are calculated from material scattered throughout mineralogical literature, and reworked to make them useful for gemologists.
Of practical interest to gem cutters is a special graph relating critical angle and refractive index. Other books list critical angles for various gems, but, because of the wide range in optical properties in certain gem species, these numbers are not always valid. The graph included here makes it possible to determine the exact critical angle to use for the specific material to be cut.
With growing interest in investment potential of gemstones, the lay public can also consult this versatile reference for information or photographs before making a decision to purchase. Collectors of gems, especially connoisseurs, will view the unique color plates of many exotic gem species with special pleasure.
About the author
Joel E Arem was awarded PhD in mineralogy at Harvard in 1970. His research specialties are crystal growth and X-ray crystal structure analysis. Dr Arem is the author of three previously published titles: Rocks and Minerals, Gems and Jewelry, and Man-made Crystals.
Friday, January 26, 2007
The Federal Trade Commission’s Guide for the Jewelry, Precious Metals and Pewter Industries
FTC writes:
23.2 Misleading illustrations
It is unfair or deceptive to use, as part of any advertisement, packaging material, label, or other sales promotion matter, any visual representation, picture, televised or computer image, illustration, diagram, or other depiction which, either alone or in conjunction with any accompanying words or phrases, misrepresents the type, kind, grade, quality, quantity, metallic content, size, weight, cut, color, character, treatment, substance, durability, serviceability, origin, preparation, production, manufacture, distribution, or any other material aspect of an industry product.
Note to 23.2: An illustration or depiction of a diamond or other gemstone that portrays it in greater than its actual size may mislead consumers, unless a disclosure is made about the item's true size.
More info @ http://www.ftc.gov/bcp/guides/jewel-gd.htm
23.2 Misleading illustrations
It is unfair or deceptive to use, as part of any advertisement, packaging material, label, or other sales promotion matter, any visual representation, picture, televised or computer image, illustration, diagram, or other depiction which, either alone or in conjunction with any accompanying words or phrases, misrepresents the type, kind, grade, quality, quantity, metallic content, size, weight, cut, color, character, treatment, substance, durability, serviceability, origin, preparation, production, manufacture, distribution, or any other material aspect of an industry product.
Note to 23.2: An illustration or depiction of a diamond or other gemstone that portrays it in greater than its actual size may mislead consumers, unless a disclosure is made about the item's true size.
More info @ http://www.ftc.gov/bcp/guides/jewel-gd.htm
Color change gemstones
Most frequently seen color change gemstones.
- Chrysoberyl (alexandrite)
- Synthetic Chrysoberyl (synthetic alexandrite)
- Color change sapphire
- Synthetic color change sapphire
- Fluorite
- Pyrope / spessartite garnet
- Herderite
- Kyanite
- Monazite
- Spinel
- Synthetic spinel
- Toumaline
- Zultanite
Other color change gemstones
- Chameleon-type diamond (after heating color changes from orange yellow to green when exposed to light).
- Mood stone (quartz glass or plastic triplet containing a layer of liquid crystal which changes color with small changes in its temperature).
- Chrysoberyl (alexandrite)
- Synthetic Chrysoberyl (synthetic alexandrite)
- Color change sapphire
- Synthetic color change sapphire
- Fluorite
- Pyrope / spessartite garnet
- Herderite
- Kyanite
- Monazite
- Spinel
- Synthetic spinel
- Toumaline
- Zultanite
Other color change gemstones
- Chameleon-type diamond (after heating color changes from orange yellow to green when exposed to light).
- Mood stone (quartz glass or plastic triplet containing a layer of liquid crystal which changes color with small changes in its temperature).
The RRUFF™ Project
The RRUFF project compiles high quality spectral data from characterized minerals worldwide with Raman Spectroscopy, X-ray Diffraction and Electron Microprobe.
Raman Spectroscopy compares their Raman spectral patterns to those from mineral samples that have been positively identified. X-ray Diffraction from powder and single crystal are used to identify and interpret the crystallographic characteristics unique to each mineral. Electron Microprobe analyses the chemical characteristics of each mineral.
The database may become a standard for gemologists, mineralogists and the general public for the identification of minerals. The database currently contains information on approximately 2000+ minerals with more added on regular basis.
The RRUFF™ project includes the research groups of Dr Robert T Downs (Geosciences, Arizona), Dr M Bonner Denton (Chemistry, Arizona), and Dr George R Rossman (Geological and Planetary Science, Caltech).
More info @ http://rruff.info
Raman Spectroscopy compares their Raman spectral patterns to those from mineral samples that have been positively identified. X-ray Diffraction from powder and single crystal are used to identify and interpret the crystallographic characteristics unique to each mineral. Electron Microprobe analyses the chemical characteristics of each mineral.
The database may become a standard for gemologists, mineralogists and the general public for the identification of minerals. The database currently contains information on approximately 2000+ minerals with more added on regular basis.
The RRUFF™ project includes the research groups of Dr Robert T Downs (Geosciences, Arizona), Dr M Bonner Denton (Chemistry, Arizona), and Dr George R Rossman (Geological and Planetary Science, Caltech).
More info @ http://rruff.info
Treasures From The Kremlin
By The Metropolitan Museum of Art, New York
1979 ISBN 0-87099-193-0
The Metropolitan Museum of Art writes:
The Kremlin in Moscow is one of the world’s greatest repositories of Russian art. Gold and silver objects of astounding beauty, arms and armor, icons, ceremonial equestrian trappings, textiles, and incomparable Russian needlework are preserved in the seven museums and churches that comprise the State Museums of the Moscow Kremlin. Magnificent objects from these, including masterworks of Western European art from the Kremlin collections, are pictured in Treasures from the Kremlin. More than two hundred illustrations, half of them reproduced in full color, reveal objects of extraordinary artistic excellence and historical significance ranging from the twelfth to the twentieth century.
Treasures from the Kremlin grew out of the great exhibition of Russian art at the Metropolitan Museum of Art in New York. Six curators of the Kremlin museums offer engrossing and authoritative essays about their individual subjects.
Starting with such fabled medieval works as the twelfth-century silver gilt chalice of Yurii Dolgorukii, founder of Moscow, and the icon The Savior of the Fiery Eye, we move on to the sixteenth and seventeenth centuries. During this period Moscow became the political, religious, and artistic center of Russia, and the decorative arts reached the height of their splendor. Within the walls of the Kremlin, the churches and palaces blazed with an incredible profusion of artworks. From the Armory, which was the private treasury of the czars, came masterworks of the goldsmith’s and armorer’s art. The damascened helmet of Ivan the Terrible’s son and the coat of mail worn by Boris Godunov are illustrated in this volume.
Here too are enameled saddles; silver bridle chains, flagons, and platters; exquisite gold liturgical vessels and pearl embroidered hangings from the Kremlin’s churches. The eighteenth and nineteenth centuries are also generously represented.
A brilliant closing note comes from the atelier of the peerless Carl Faberge—and early twentieth- century representation of the Kremlin itself, executed in gold and jewels.
A selected bibliography and an index of Russian names further enhance the scope of Treasures from the Kremlin.
1979 ISBN 0-87099-193-0
The Metropolitan Museum of Art writes:
The Kremlin in Moscow is one of the world’s greatest repositories of Russian art. Gold and silver objects of astounding beauty, arms and armor, icons, ceremonial equestrian trappings, textiles, and incomparable Russian needlework are preserved in the seven museums and churches that comprise the State Museums of the Moscow Kremlin. Magnificent objects from these, including masterworks of Western European art from the Kremlin collections, are pictured in Treasures from the Kremlin. More than two hundred illustrations, half of them reproduced in full color, reveal objects of extraordinary artistic excellence and historical significance ranging from the twelfth to the twentieth century.
Treasures from the Kremlin grew out of the great exhibition of Russian art at the Metropolitan Museum of Art in New York. Six curators of the Kremlin museums offer engrossing and authoritative essays about their individual subjects.
Starting with such fabled medieval works as the twelfth-century silver gilt chalice of Yurii Dolgorukii, founder of Moscow, and the icon The Savior of the Fiery Eye, we move on to the sixteenth and seventeenth centuries. During this period Moscow became the political, religious, and artistic center of Russia, and the decorative arts reached the height of their splendor. Within the walls of the Kremlin, the churches and palaces blazed with an incredible profusion of artworks. From the Armory, which was the private treasury of the czars, came masterworks of the goldsmith’s and armorer’s art. The damascened helmet of Ivan the Terrible’s son and the coat of mail worn by Boris Godunov are illustrated in this volume.
Here too are enameled saddles; silver bridle chains, flagons, and platters; exquisite gold liturgical vessels and pearl embroidered hangings from the Kremlin’s churches. The eighteenth and nineteenth centuries are also generously represented.
A brilliant closing note comes from the atelier of the peerless Carl Faberge—and early twentieth- century representation of the Kremlin itself, executed in gold and jewels.
A selected bibliography and an index of Russian names further enhance the scope of Treasures from the Kremlin.
Thursday, January 25, 2007
New Technologies In Gemology
According to Emmanuel Fritsch of The Institute des Materiaux Jean Rouxel in France, gem identification may become user / consumer-friendly in terms of cost, availability and practical application with the following analytical techniques:
- Luminescence
- Laser Breakdown Spectroscopy (LIBS)
- Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS)
- Energy Dispersive X-ray Fluorscence (EDXRF)
- Isotopic Analysis
The analytical techniques may be useful to map gemstone properties, country of origin, and also the specific mine.
- Luminescence
- Laser Breakdown Spectroscopy (LIBS)
- Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS)
- Energy Dispersive X-ray Fluorscence (EDXRF)
- Isotopic Analysis
The analytical techniques may be useful to map gemstone properties, country of origin, and also the specific mine.
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