In mid-2012, one of the international diamond grading laboratories in Antwerp reported undisclosed CVD synthetic diamonds, causing a stir in the diamond industry.
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The Gem Testing Laboratory of Jaipur, India, received for identification an opaque blue specimen, submitted as sapphire.
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A study of the nacre and the cavity of a large Pinctada maxima cultured pearl yields a theory on the specimen’s formation.
Read MoreNatural and synthetic gem rubies can be separated on the basis of their trace-element chemistry.
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Provides criteria for detecting the resin filling of turquoise, an advanced treatment that reduces porosity and can dramatically improve appearance and stability.
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Two pearls presented a unique challenge, as testing at three different gemological laboratories could not conclusively identify them as natural or cultured, determine a freshwater or saltwater growth environment, or specify the producing mollusk.
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Abstracts of speaker presentations from the “Diamond Identification” session of GIA’s 2018 International Gemological Symposium.
Read MoreGemological photojournalist Robert Weldon shares the stories behind some of his favorite photos.
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G&G announces the winners of the Dr. Edward J. Gübelin Most Valuable Article Awards for 2019.
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Reports on the microscopic, chemical, and spectroscopic features that differentiate the high-quality Baw Mar sapphire from “classic” gem-quality Burmese sapphire.
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