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Research & News
Gem News International
New Emerald Locality in Southern California
An emerald containing an unusual citrine inclusion heralds a new pegmatitic deposit in the Julian Mining District in San Diego County.
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Webinar Series
GIA Knowledge Sessions
Engage in webinars on the most diverse and pressing issues in gemology today, including gemstone origin, laboratory-grown stones and new discoveries in field gemology.
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Lab Notes
Blue “Graining” in Green-Yellow Diamond
Unusual color zoning likely indicates multiple treatments of a Fancy Intense green-yellow diamond.
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Micro-world
Inclusions in Kenyan Rubies from the John Saul Mine
Very similar inclusion scenes featuring needles and thin films make rubies from Kenya hard to distinguish from Mogok rubies.
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Press Release
Study of Rare Diamonds Unlocks More of Earth's Secrets
Scientists at GIA continue to delve deep into earth's geologic history, using diamonds' distinctive characteristics to go – virtually – where no scientist has ever gone.
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Lab Notes
Large Type IIa Diamond from Arkansas, USA
A surprising find from Crater of Diamonds State Park reveals a natural diamond remarkable in both size and clarity for its U.S. origin.
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