gems, Arabic mineralogy, al-Biruni, corundum, spinel, pearl, early lapidaries

Belenitskii surveys al-Bīrūnī’s eleventh-century mineralogical treatise, Kitāb al-Jamāhir fī maʿrifat al-jawāhir [Book of the Multitude of Knowledge of Precious Stones], emphasizing its importance as a major medieval work on minerals, gemstones, and metals. He discusses al-Bīrūnī’s combination of information derived from earlier Greek, Arabic, Persian, and Indian authorities with direct observation and practical knowledge obtained from merchants, jewelers, craftsmen, and miners. Particular attention is given to the empirical character of al-Bīrūnī’s work: the description and differentiation of minerals by color, transparency, hardness, density, and other physical properties, together with his unusually accurate determinations of specific gravity. The treatise also preserves extensive information on the sources, varieties, working, uses, trade, and values of precious stones and metals. Belenitskii presents the work as an important stage in the development of scientific mineralogy in the medieval Islamic world and as evidence of al-Bīrūnī’s critical and observational approach to traditional mineralogical knowledge.