Precious Stones and Numbers : The Vedic View
Varha Mihir, the famous astrolager of ancient India, who flourished in the 1st century BC, has devoted a full chapter to gems and precious stones in his monumental work Brihat Samhita. He has given detailed characteristics of diamonds, blue sapphires,emeralds, and other gems. He has also explained how different gems are associated with different deities, and has prescribed the colour of gem suitable for each caste.
According to the Vedic system, there are nine basic gems: (i) ruby; (ii) pearl-real, not cultured; (iii) coral; (iv) emerald; (v) yellow sapphire called Pukharaj in India; (vi) diamond; (vii) blue sapphire (viii) Gomed (Sanskrit name)- it is like a garnet in appearance but different from it; (ix) Cat's eye.