gems, Arabic mineralogy, al-Biruni, early lapidaries

Wiedemann presents notes toward a history of mineralogical knowledge among Muslim scholars, drawing particularly on a Gotha manuscript containing material attributed to ʿAlī ibn Aidamur ibn ʿAlī al-Gildakī and on fragments of al-Kindī’s mineralogical writings preserved by later authors. [208–209] Al-Kindī’s work is described as containing what Wiedemann considers among the earliest Muslim accounts of minerals in this field, including observations on the value and properties of diamonds, pearls, and turquoise. Pearls are said to come from Muscat, with the finest occurring between the mouth and ear of the shellfish; turquoise is described as changing color with weather, being affected by musk and water, and damaged by oil or fat. [209] Al-Kindī divides gemstones (ǧauhar) into those derived from animals and those from the earth, and the latter into transparent and opaque varieties. Pearls belong to the animal group; transparent stones are divided into precious and non-precious classes, with the precious stones including diamond among those that cut, and hyacinth, zircon, and emerald among those that do not. Hyacinth is further divided into red, yellow, sky-blue, and white varieties, each with numerous shades, illustrating the highly developed discrimination of color nuances in the Oriental gem trade. Carnelian, amber, and onyx are included among lesser stones, while coral is classified with plants. [210] Wiedemann also records al-Gildakī’s observations on glass, including its ability to be colored and molded and its behavior when heated, and cites al-Muqaddasī on naturally greenish glass from the Persian desert. The article concludes with a discussion of amber, including its medicinal and talismanic uses and the names applied to it by Byzantine and Arabic writers. [211]