An object capable of being used as a personal ornament that has formed spontaneously in nature without human intervention and has the qualities of beauty, rarity, hardness, inalterability and wearability.

Almost all gems are minerals, more rarely rocks, but some materials of organic origin are also considered gems even though they are not transparent; the latter include jet, ivory, amber, coral and pearls.

There was undoubtedly a profound relationship between primitive man and gems, especially in religious rituals and ornamental use. History documents the mystic and artistic use of stones in the great early civilisations: Assyria, Babylon, Egypt, China, India, Persia, Israel, Greece, Rome. There is considerable mention of gems in the Bible.