A plastic product that mimics the play-of-color phenomenon of natural opal but has distinctly different gemological properties is now available to consumers.
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A garnet proves to have a much higher grossular component than initially expected.
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Shows how genetic material extracted from small amounts of pearl powder can be a useful indicator of this akoya cultured pearl species.
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Analyzes the substructures that cause the intense iridescence observed in “rainbow” hematite from Minas Gerais, Brazil.
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Characterizes diamonds with exceptionally rare natural green color, based on GIA’s extensive database of samples.
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The material used to fill a large fracture in a diamond yields an unexpected iridescence under two different illuminations.
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A CVD-grown diamond shows an unexpected treatment-caused color.
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The examination of two unusual garnets results in identifications issued for the first time in GIA's colored stone report records.
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An HPHT-treated round brilliant diamond with an inscription that presents as a GIA report number is found to be inconsistent with the institute's report, previously issued for an untreated diamond.
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The GIA lab examines five gem-quality CVD-grown diamonds in sizes that reflect the improving technology of the synthetic gemstone industry.
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past gems & gemology issues
Winter 2024
Volume 60, Issue 4
Fall 2024
Volume 60, Issue 3
Summer 2024
Volume 60, Issue 2
Spring 2024
Volume 60, Issue 1
Winter 2023
Volume 59, Issue 4
