it's determined based on the Gemological Institute of America's diamond color scale. In this grading system, stones are evaluated on a scale of D to Z, with D representing colorless stones.

Consumers will recognize the standard ‘4Cs' used in diamond grading - cut, clarity, carat and color - in the reports, along with Charles & Colvard moissanite-specific grading measures." ...

The extremely rare gem, which has a VS2 clarity, has received the highest possible color grading for a blue diamond from the Gemological Institute of America. Better still: The stone is also ...

According to the Gemological Institute of America (GIA), The Mediterranean Blue exhibits the highest possible color grading for a blue diamond. Its cushion-shaped cut enhances its saturation and ...

The Winston Red is now on public display at the Smithsonian InstitutionCarlsbad, Calif., April 08, 2025 (GLOBE NEWSWIRE) -- A team of scientists from the Gemological Institute of America (GIA), ...