Analysis of a 5.03 ct HPHT-grown blue synthetic diamond, the largest ever examined by GIA.
Read MoreObserving a water drop’s interaction with opal, as well as refractive index, can confirm a specimen’s hydrophane nature with less risk of breakage than total immersion.
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A fingerprint pattern, possibly left by human skin oils during the assembly process, is observed in natural turquoise beads.
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An unusual laser manufacturing remnant, possibly once used to guide a gem cutter, was left behind in a clock-like shape.
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The New York lab received four baroque-shaped pearls with damaged nacre layers
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Recent lab examination reveals that traditional treatments such as calcium fluoride coating are still prevalent in the trade, and great care must be taken to identify them.
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A report on a 1,138 ct rough diamond, possibly the largest ever examined by GIA.
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This section, from the Spring 1991 issue of Gems & Gemmology, is a compilation of interesting finds from GIA’s laboratories.
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