Research & News
Blue Zircon Reportedly from Malawi
A reported new source of blue zircon in Malawi yields rough material for beautiful finished stones in the gem trade.
GIA Knowledge Sessions
Engage in webinars on the most diverse and pressing issues in gemmology today, including gemstone origin, laboratory-grown stones and new discoveries in field gemmology.
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.