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

Lemmlein examines the mineralogical information contained in al-Bīrūnī’s Kitāb al-Jamāhir fī maʿrifat al-jawāhir, assessing the work from the standpoint of modern mineralogy and the history of science. He considers al-Bīrūnī’s descriptions and identification of gemstones, minerals, metals, and alloys, including their colors, physical characteristics, localities, methods of extraction and working, and commercial uses. Particular attention is given to al-Bīrūnī’s quantitative investigations of specific gravity, which represent an unusually advanced experimental approach for the eleventh century, and to his attempts to distinguish minerals through observable and measurable properties rather than relying solely on traditional lapidary lore. Lemmlein also discusses the difficulties of correlating medieval Arabic mineral names with modern species and emphasizes al-Bīrūnī’s critical use of earlier authorities, craftsmen’s knowledge, and his own observations and experiments. The article presents the Jamāhir as one of the most important medieval contributions to mineralogy and gemology.