News & Articles


CVD Diamond Over 34 Carats Examined in GIA’s Hong Kong Laboratory
A look at the largest CVD diamond GIA has encountered to date.
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Color Modification of Spinel by Nickel (Ni) Diffusion: A New Treatment in the Gem Market
GIA researchers report on a new nickel-diffusion treatment used to modify color in spinel and present criteria for identification.
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An Update on Sapphires with Unstable Color
Unexpected behavior is observed in sapphires submitted to GIA for color stability testing.
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