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 ArticlesPolish 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 ArticlesRumors 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 ArticlesDuring 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 ArticlesThe 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 ArticlesThe 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…
Featured ArticlesLighting directly affects both the beauty and value of your gemstones and jewelry as well as the psychological well being of your clients and staff. In the last two issues of this series we have…
Featured ArticlesIn April 2008, gem dealer David Sherman sued the Gemological Institute of America, the American Gem Trade Association,and several of the officers of the latter organization. The officers were named due to their role as…
Featured ArticlesOne recent technological development is that of rare earth magnets, which have incredible strength and stability, even in small sizes. While commonly nickel plated, these magnets are made of neodymium, iron, and boron (NdFeB) and…
Featured ArticlesGemstones can look dramatically different when viewed in different lighting conditions. The perceived color can make a huge difference when grading and pricing these gems. Understanding what light sources to use first requires a knowledge…
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