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).
Friday, January 26, 2007
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.
About Men
I like a man who's good, but not too good--for the good die young, and I hate a dead one.
- Mae West
- Mae West
Gem Cutting
By John Sinkankas
A Lapidary’s Manual
Van Nostrand Reinhold Company
1984 ISBN 0-442-27630-3
Van Nostrand Reinhold Company writes:
What could be a more helpful tool for the lapidarist, beginner or expert, than this new edition of the gem cutter’s bible?
This expanded and updated volume thoroughly examines advances in the lapidary arts over the past twenty years. Recent discoveries of natural gemstones—some of them previously unknown in lapidary quality—plus the production of synthetic gemstones and the increased use of diamond abrasives and polishing agents are investigated in this classic guide to properties and treatments of gem materials.
This reference manual, packed with over 200 illustrations, continues to stress simplicity in equipment and technique. Gem cutting methods that have withstood the test of time are given with crystal clear instructions. Useful money-saving tips on how to make lapidary tools are included as well. Expert gemologist John Sinkankas provides valuable guidance on:
- gemstones—sawing, grinding, lapping, sanding, polishing, and drilling
- cabochons and how to cut them
- faceted gems—how to cut them and the equipment for cutting
- spheres and beads
- tumbling
- carving and engraving
- mosaic and inlay work
The last chapter provides a summary of many dozens of gem materials and how they may be successfully cut, the result of Sinkankas’s many years of hands on experience.
About the author
John Sinkankas is the author of the first two editions of Gem Cutting, published by Van Nostrand Reinhold, as well as many other books over 100 articles for popular and scientific journals.
A Lapidary’s Manual
Van Nostrand Reinhold Company
1984 ISBN 0-442-27630-3
Van Nostrand Reinhold Company writes:
What could be a more helpful tool for the lapidarist, beginner or expert, than this new edition of the gem cutter’s bible?
This expanded and updated volume thoroughly examines advances in the lapidary arts over the past twenty years. Recent discoveries of natural gemstones—some of them previously unknown in lapidary quality—plus the production of synthetic gemstones and the increased use of diamond abrasives and polishing agents are investigated in this classic guide to properties and treatments of gem materials.
This reference manual, packed with over 200 illustrations, continues to stress simplicity in equipment and technique. Gem cutting methods that have withstood the test of time are given with crystal clear instructions. Useful money-saving tips on how to make lapidary tools are included as well. Expert gemologist John Sinkankas provides valuable guidance on:
- gemstones—sawing, grinding, lapping, sanding, polishing, and drilling
- cabochons and how to cut them
- faceted gems—how to cut them and the equipment for cutting
- spheres and beads
- tumbling
- carving and engraving
- mosaic and inlay work
The last chapter provides a summary of many dozens of gem materials and how they may be successfully cut, the result of Sinkankas’s many years of hands on experience.
About the author
John Sinkankas is the author of the first two editions of Gem Cutting, published by Van Nostrand Reinhold, as well as many other books over 100 articles for popular and scientific journals.
The Federal Trade Commission’s Guide for the Jewelry, Precious Metals and Pewter Industries
FTC writes:
23.1 Deception (general)
It is unfair or deceptive to misrepresent the type, kind, grade, quality, quantity, metallic content, size, weight, cut, color, character, treatment, substance, durability, serviceability, origin, price, value, preparation, production, manufacture, distribution, or any other material aspect of an industry product.
Note 1 to 23.1: If, in the sale or offering for sale of an industry product, any representation is made as to the grade assigned the product, the identity of the grading system used should be disclosed.
Note 2 to 23.1: To prevent deception, any qualifications or disclosures, such as those described in the guides, should be sufficiently clear and prominent. Clarity of language, relative type size and proximity to the claim being qualified, and an absence of contrary claims that could undercut effectiveness, will maximize the likelihood that the qualifications and disclosures are appropriately clear and prominent.
More info @ http://www.ftc.gov/bcp/guides/jewel-gd.htm
23.1 Deception (general)
It is unfair or deceptive to misrepresent the type, kind, grade, quality, quantity, metallic content, size, weight, cut, color, character, treatment, substance, durability, serviceability, origin, price, value, preparation, production, manufacture, distribution, or any other material aspect of an industry product.
Note 1 to 23.1: If, in the sale or offering for sale of an industry product, any representation is made as to the grade assigned the product, the identity of the grading system used should be disclosed.
Note 2 to 23.1: To prevent deception, any qualifications or disclosures, such as those described in the guides, should be sufficiently clear and prominent. Clarity of language, relative type size and proximity to the claim being qualified, and an absence of contrary claims that could undercut effectiveness, will maximize the likelihood that the qualifications and disclosures are appropriately clear and prominent.
More info @ http://www.ftc.gov/bcp/guides/jewel-gd.htm
Aventurescent Gemstones
Most frequently seen aventurescent gemstones
- Aventurine quartz (quartzite)
- Sunstone (oligoclase or labradorite feldspar)
Imitation aventurine gemstones
- Goldstone (man-made aventurine glass)
- Aventurine quartz (quartzite)
- Sunstone (oligoclase or labradorite feldspar)
Imitation aventurine gemstones
- Goldstone (man-made aventurine glass)
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