DIAMOND, the most highly valued of precious stones. The finest diamonds are perfectly transparent and colourless, of a regular form, and entirely free from flaws and veins. They have been distinguished by lapidaries into oriental and occidental. But these terms are not expressive of the country from which they are brought, but merely of their qualities and value, the oriental being reckoned the finest and hardest, and the occidental of inferior value. See CHEMISTRY and MINERALOGY Index.