Book of Royal Gemstones
This work, by Abu al-‛Abbās Ahmad b. Yūsuf al-Qaysī al-Tīfāshī, a 13th-century writer and mineralogist who was born in Tunisia and worked in Egypt, describes precious gems found in the treasuries of kings and rulers. The author lists 25 gemstones and dedicates a chapter to each. They include the ruby (yāqūt), emerald (zumurrud), topaz (zabarjad), diamond (almās), turquoise (fīrūzaj), magnetite (maghnātīs), agate (‛aqīq), lapis lazuli (lāzward), coral (marjān), and quartz (talq). In each chapter, the author discusses the causes of the gemstone’s formation, provenance, criteria for appraisal of ...