What’s New With Cobalt?
By now, we should all be aware of last years discovery of the use of cobalt coatings to improve the color of Tanzanite. This treatment, as reported by the AGTA-GTC and the AGL (May 23…
Featured ArticlesThe “Crown of Light” Diamond (And Other Caribbean Questions)
The story here on the "Crown of Light" diamond is part Gem Note and part Appraisers Notebook. What is it? Who is selling it? How much is it worth? Jewelers and appraisers are often quick…
Featured ArticlesAGA Conference Report
The Accredited Gemologists Association held its annual winter Conference in Tucson on Wednesday February 4. The successful conference featured several speakers from the International gemological community. American Gemological Laboratories Vice President Christopher Smith this years…
Featured ArticlesUnderstanding the Burma Embargo
Cecilia Gardner, President, CEO & General Counsel for the Jewelers Vigilance Committee hosted an informational presentation on the “The Tom Lantos Block Burmese JADE Act of 2008.†The program was offered in cooperation with the…
Featured ArticlesThe International School of Gemology Responds to the Synthetic Tourmaline Article
We have had many contacts over our previous questions regarding that group of tourmalines that gave the anomalous reactions to the Raman, immersion cell, and virtually all other tests. At one point we raised the…
Featured ArticlesSymmetry and the Polished Diamond
Polish and symmetry errors affect the perceptible appearance of a diamond. Off center culets, lopsided pavilions, off center tables, and lopsided crowns all detract from the overall beauty. During several visits to prominent manufacturing centers, I…
Featured ArticlesSynthetic Tourmaline-Rumors and Reality
Rumors spread like wildfire on the Internet. Knowledgeable gemologists cannot be criticized for believing what appear to be well-researched facts coming from seemingly reliable sources, especially when backed by high tech equipment. Case in point…
Featured ArticlesTrade Alert: Flux grown synthetic red spinels again on the market
During and after the Hong Kong Jewellery Fair in September the SSEF Swiss Gemmological Institute received several red spinels for testing, which were found to be flux synthetic spinels. These spinels apparently have been offered…
Featured ArticlesRubies, Emeralds, Sapphires, Diamonds & Pearls
The first gem conference co-hosted by Gemworld and the AGTA Gemological Testing Center was a great success. Knowledge was shared by industry speakers on the title topics. The theme was Integration of Information and topics…
Featured ArticlesDiamond Proportions: Why the average works
The positive or negative effect these features have on our overall impression can, and often will, overwhelm all the other factors to a degree, causing our minds eye to focus on the one feature. This…
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