History of Technology in India, Vol. I: From Antiquity to c. 1200 A.D. v1.c17.s3.t1.7

v1.c17.s3.t1.7

Beryl, *vaidūrya* in Sanskrit, has a hardness (7³/₄) different from those of chrysoberyl (8¹/₂) and quartz (7), and the modern literature does not indicate that chatoyancy is observed in any beryl sample. However, green chrysoberyl sometimes looks like green beryl, and since the former gem exhibits chatoyancy effect occasionally, the Indian word *vaidūrya* has in some instances been used (unfortunately) to indicate cat’s eye gem also. Buddhabhaṭṭa’s writing (Ratnaparīkṣā or RP 200) created this confusion for the first time.