corundum, history.1, gems

The Agni Purana, (Sanskrit: अग्नि पुराण, Agni Purāṇa) is an English prose translation of one of the major Sanskrit Purāṇas and an encyclopedic compilation covering mythology, ritual, cosmology, medicine, architecture, statecraft, astronomy and numerous practical arts. Of particular gemological importance is the section on ratna-parīkṣā (“testing of gems”), which lists stones appropriate for royal use, including diamond, emerald, ruby, pearl, sapphire, lapis lazuli, crystal and several less readily identifiable materials. Good gems are characterized generally by internal lustre, purity and well-formed shape, while dull, cracked or included stones are rejected. Diamond is praised when pure, unbreakable, bright and exhibiting rainbow-like lustre; emerald should possess a parrot-green hue, gloss and radiance; rubies are classified partly according to their supposed sources and colors; and pearls are valued for roundness, whiteness, transparency and weight, with both naturalistic and legendary origins being recorded. Sapphire is described in terms of its strong color and lustre, while lapis lazuli is recommended for necklaces and other ornaments. The passage is valuable less as mineralogy in the modern sense than as evidence for early Indian systems of gem classification, quality assessment, auspiciousness and the close association of precious stones with kingship and personal fortune.