A Survey of the Gemstone Resources of China
China has identified many deposits with significant potential to produce gemstones; various species are discussed.
A Gemological Study of Turquoise in China
Chinese gem-quality turquoise is sky blue, greenish blue or bluish green in colour.
The Identification of Zachery-Treated Turquoise | Gems & Gemmology
Millions of carats of turquoise have been enhanced by a proprietary process called the Zachery treatment.