Turquoise from Western Arkansas
A report on turquoise from the only known U.S. deposit outside of the Southwest.
Impregnated and Dyed Turquoise
Natural turquoise has been subjected to dyeing and three types of impregnation.
The Identification of Zachery-Treated Turquoise | Gems & Gemology
Millions of carats of turquoise have been enhanced by a proprietary process called the Zachery treatment.
Abstracts; Winter 1991
This article, from the Winter 1991 issue of Gems & Gemology, is a compilation of abstracts of important gemology-related articles published outside of Gems & Gemology.