Coatings: A New Tanzanite Treatment Uncovered CAMEO

A new treatment: coated Tanzanite

Coatings used to give tanzanite a deeper (blue) color? The American Gem Trade Association Gemological Testing Center (AGTA-GTC) and American Gemological Laboratories (AGL) received a number of faceted tanzanite samples recently in New York that were determined to have been treated with a coating. Evan Caplan of Omi Gems Inc. sent samples to several labs […]

Continue reading »