Geographic Origin of Diamond,
Sapphire from China, and Gems on Canvas
New Gems & Gemology IssueREAD MORE
Research & News
Gems on Canvas
Explores the use of gem materials as pigments in works of art, from the earliest cave paintings to the modern era.
GIA Knowledge Sessions
Engage in webinars on the most diverse and pressing issues in gemology today, including gemstone origin, laboratory-grown stones and new discoveries in field gemology.
Chondrodite in Red Spinel from Mogok, Myanmar
The Bangkok lab recently encountered a single round crystal of chondrodite in red spinel, a possible indicator of Burmese origin.
Two Antique Mughal Spectacles with Gemstone Lenses
Unique diamond and emerald-lensed spectacles from the Mughal Empire were tested in GIA’s New York laboratory.
Colored Stones from the Deep
The first installment of this column discusses the formation of colored stones from the crust-mantle transition and below.
Radioactive Green Diamond
The Carlsbad lab recently encountered a 2.42 ct green diamond showing signs of radiation treatment by the use of radioactive salts.