Minerals and Metals in Ancient India v2.c43.s3.t1.5

v2.c43.s3.t1.5

Śilappadikaram was probably the first text classifying diamond into four ‘castes’: brāhmaṇa, white and light yellow; kṣatriya red; vaiśya dark yellow or smoky and śūdra, black or impure. This casteist slant in gemmology persisted for more than a millennium.