Reference work entry
Turquoise is regarded as a variety of jade by gemstone craftsman in China. It is a phosphate of copper and aluminium in the form of cryptocrystalline blocks or nodules with different shades of blue or green. It has a Mohs hardness of 5–6, a waxy lustre and a fine texture. It was used for decorative purposes with green jade and agate during the Neolithic age. Yun County in Hubei Province is famous for its high-quality turquoise. Recently, turquoise has also been found in Shaanxi, Xinjiang, Anhui and Henan Provinces. The world’s most famous turquoise is produced in Persia (Iran). Because Persian turquoise has long been exported to European countries via Turkey, this gemstone is called ‘Turkey Jade’ or ‘Turkish Jade’ (Fig. 32).
© Springer Nature Singapore Pte Ltd. 2020