The ruby is the world's most precious and rare stone. For the ancient Hindus, the ruby was Rajnapura: the Gem of Gems, at whose heart surges an eternal, unquenchable flame. Yet, for all its rarity and beauty, the ruby has always been a slightly sinister stone. Indian legend says the ruby was born from the blood of a demon. Indeed, the ruby is very close to a wild, living being: fiery, passionate, and dangerous. It has been at the center of love and...