Chinese Porcelain Turquoise Ground Bowl. Decorated with floral imagery. Qianlong mark on bottom. 

Size: 8 1/4 X 8 1/4 X 3 in. 

#7093 . 

According to ancient literature, turquoise has been known in China for more than 3,000 years. In 1977, more than 1,000 turquoise relics in the forms of cicadas, frogs, and other animals were unearthed from ruins dating to the Yin Dynasty (about 1300 BC) in Anyang, Henan. Today, significant quantities of gem quality turquoise are being mined at Yunxian and Zhushan in Hubei Province. Chinese gem-quality turquoises are light sky blue, greenish blue, and bluish green in color. Gem-quality Chinese turquoise is relatively pure and tough, with a fine and smooth appearance like jade, simple and elegant in color, and glittering like porcelain when polished. In China, turquoise with a Mohs hardness above 5 is known as “porcelain turquoise,” of which those specimens with a brilliant, unadulterated sky blue color are considered highest in quality. Less desirable is the turquoise with a hardness below 4.5 and those specimens that have been faded by weathering. Turquoise that is reticulated with fine-veined limonite (ferrian lines) is referred to by jewelers as “spiderweb turquoise.” Specimens with clean, sharp lines are considered the finest quality.