Research & News
Reports on a newly discovered treatment process for producing a deep blue color in natural spinel and proposes identification criteria.
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.
CVD Diamond Over 34 Carats
A look at a 34.59 ct CVD-grown diamond examined at GIA’s Hong Kong laboratory.
Rainbow Mountain in Natural Diamond
An iridescent feather inclusion in natural diamond bears resemblance to Rainbow Mountain in Peru.
Gems Formed in Metamorphic Rocks
Gemstones formed in metamorphic environments offer insights into the earth’s history and the evolution of tectonic activity that led to their formation.
Characteristics of Treated Rubies from Greenland
An overview of the treatment process of ruby and pink sapphire from Greenland and its effect on inclusion scenes and chemistry.