BACKGROUND The Xichuan turquoise mining area in Henan Province belongs to the east extension of the turquoise metallogenic belt in the junction of Hubei and Shaanxi Provinces. A lot of turquoise artifacts have been excavated in many early archaeological sites near Xichuan. Therefore. the distribution of the Xichuan turquoises has attracted wide attention of many archaeologists. https://www.parisnaturalfoodes.shop/product-category/tri-chromium/