gems, turquoise, Iran, Persia, Persian turquoise

This article surveys the history, nature, sources, mining, preparation, and trade of turquoise. It distinguishes the true mineral turquoise, principally obtained from Persia, from the so-called “occidental” or “new-rock” turquoise then believed to consist largely of fossil animal teeth or bones colored by copper compounds, and summarizes contemporary mineralogical analyses and differing theories concerning the latter material. Particular attention is given to the Persian turquoise mines near Nishapur in Khorassan, drawing chiefly on the accounts of travellers and mineralogists including Morier, Fraser, and Agaphi of Moscow. Six mines are described, with the Madan-i-alia or “black mine” identified as the principal working; turquoise occurs in veins and irregular masses in porphyritic rock. Mining is portrayed as primitive and dangerous, without systematic shafts or galleries, while ownership and revenues are controlled by the Persian government and the mines are worked communally by local villagers. The turquoise is sorted into three commercial classes according to size, form, color, and quality, after which much of the production is sent to Meshed, where specialized craftsmen cut and polish the stones using simple lapidary equipment. Finished gems are commonly fashioned as rings and distributed through India, Persia, Bukhara, and other markets, with differences in regional taste affecting their value: Persian and Turkish buyers favor purity of color, while Indian consumers particularly prize stones bearing small white spots because of their supposed talismanic qualities.