Exceptionally Rare Pearls from ECIJA
New Find of Petroleum-Included Quartz from Madagascar
Gemological Characterization of Montana Sapphire from the Secondary Deposits at Rock Creek, Missouri River, and Dry Cottonwood Creek
Examines the mining history and geological characteristics of the three secondary sapphire deposits in the state of Montana, as well as the properties of these sapphires (unheated and heat-treated).
Plastic Deformation: How and Why Are Most Diamonds Slightly Distorted?
Ethical Supply Chain Practices in Africa with Virtu Gem
A look at Virtu Gem, a company dedicated to improving artisanal mining practices in Africa.
Microscopic Shells in Natural Pearls from Pinctada radiata
Two pearls from Bahrain containing minute shells are examined at GIA’s Mumbai laboratory.
Pinctada radiata Atypical Bead Cultured Pearls from the UAE
GIA’s Mumbai laboratory reports on pearl samples from a culturing experiment by the Suwaidi Pearl Farm in the UAE.
Quarterly Crystal: Columbite(?) in Beryl
Examination of a gem-quality aquamarine crystal reveals an inclusion cluster presumed to be columbite.
A “Flying Insect” in Diamond
A partially exposed orange garnet inclusion with surrounding fractures resembles a flying insect in a brownish yellow diamond.
Morphology of Colombian Emerald: Some Less-Common Cases and Their Growth and Dissolution History
Evaluates the growth mechanisms of special morphological features in Colombian emerald, including possible relationships to trapiche emeralds and samples displaying the gota de aceite effect.
Fall 2022 Auction Highlights
A successful spring season set high expectations for colored diamonds at auction in late 2022.
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