Although Arab contribution to the sciences is generally well known in the Western world, Arab contributions to the study of gemology are less recognized because of the lack of English-language translations of notable Arab texts. Scarecrow Press is pleased to present Samar Najm Abul Huda's translation of Ahmad ibn Yusuf al Tifaschi's study of gems. Born in 1184, Al Tifaschi first learned about gems from his father, and augmented his knowledge through readings of Aristotle, Theophrastus, and Pliny, as well as through extensive travels to mines and trading centers. In 1253, he wrote what later became known as the most methodical and complete work on precious stones. Gemologists of today are still astounded by the advanced observations that Al Tifaschi made in this work. The book covers 25 different stones, giving the crystallographic forms and physical properties such as hardness, lustre, and dispersion. The book also describes causes of the formation of gemstones within their mother rocks as well as the characteristics of the mine concerned. Abul Huda's translation of the work includes notations on the translations of Al Tifaschi's work into other languages, as well as background information on Al Tifaschi's world, the well-known gemstones of the 13th century, the gemological terminology used by the medieval Arabs, and notations on other gemstones not mentioned by Al Tifaschi. Includes index, a general bibliography, and illustrations of two precious gemstones in their settings.