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FANCY COLOR DIAMOND
Dazzling brilliance. Captivating color. The planet’s most valued gems are fancy color diamonds.
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Treated Pink Diamond with HPHT Synthetic Growth Structure
A Fancy pink type IIa diamond showing cuboctahedral growth and greenish blue phosphorescence is shown to be a natural, treated colored diamond.
Spring 2024 Auction Highlights
Several lots sold during the spring auction season far exceeded their presale estimates.
Fall 2023 Auction Highlights
Large blue and pink diamonds were among the top lots of the fall auction season, including the most expensive auction jewel of 2023.
Brown Zoning in Diamond
Strong linear brown zoning is observed in a Fancy Dark yellow-brown diamond.
The Identification of Artificial Coloration in Diamond
The source of color in some diamonds, particularly fluorescent green and some yellow stones, can be very difficult to identify despite increasing knowledge about the radiation-related bands seen in the visible spectra of diamonds.
Winter 1995 G&G; Lab Notes
This section, from the Winter 1995 issue of Gems & Gemology, is a compilation of interesting finds from GIA’s laboratories.
Winter 2006 G&G Lab Notes
This section, from the Winter 2006 issue of Gems & Gemology, is a compilation of interesting finds from GIA’s laboratories.
Winter 1990 G&G; Lab Notes
This section, from the Winter 1990 issue of Gems & Gemology, is a compilation of interesting finds from GIA's laboratories.
Winter 1991 G&G; Lab Notes
Winter 1989 G&G Lab Notes
This section, from the Winter 1989 issue of Gems & Gemology, is a compilation of interesting finds from GIA's laboratories.
