Conservation Concerns over Use of Tridacna Shell in Imitation Pearls
The New York lab investigates the use of the shells of Tridacna species as imitation pearls.
Large Natural Quahog Pearl
A purple non-nacreous specimen is revealed to be a natural northern quahog pearl.
Diamond in Diamond
A Fancy black round brilliant diamond has an inclusion that is revealed to be a natural diamond crystal.
HPHT Synthetic Diamond Melee in High-Quality Jewelry Piece (英語)
The New York lab discovers a synthetic melee diamond in a pendant, underscoring the importance of testing for undisclosed synthetics.
Large HPHT-Grown Synthetic Diamonds Examined in GIA’s Hong Kong Laboratory (英語)
Examination of the largest HPHT synthetic diamonds GIA has examined so far demonstrated significant progress in this growth technology.
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