Arab Roots of Gemology
Ahmad ibn Yusuf Al Tifaschi's Best Thoughts on the Best of Stones
Samenvatting
Ahmad ibn Yusuf Al Tifaschi was born in 1184 and wrote this authoritative text in 1253. Twentieth century gemologists are astounded by the observations that he made and his contribution to gemology, whilst recognised in the Arab-speaking world, is not so well-known in the West.

