Onyx was very popular with the ancient Greeks and Romans. The name comes from the Greek word 'onyx', which means nail or claw. The story is that one day the frisky Cupid cut the divine fingernails of Venus with an arrowhead while she was sleeping. He left the clippings scattered on the sand and the fates turned them into stone so that no part of the heavenly body would ever perish. But in Greek times, almost all the colours of chalcedony from fingernail white to
dark brown and black were called onyx. Later, the Romans narrowed the term to refer to black and dark brown colours only. onyx is similar to agate. But it has straight rather than curved bands,
onyx is generally carve as small sculptures and intaglios or may be polished, tumbled or cut as beads. They are renowned as excellent materials for inlay work. Since ancient Egyptian times onyx has been stained to enhance its color. Much onyx has been produced by soaking agate in a sugar solution, then heating it in sulphuric acid to carbonize the sugar particles. Onyx seals are very popular with the Romans, who carved the pattern of the seal in negative relief to give a raised print. They often used stones with different layers, each of different color, which were then individually carved to produce a different pattern in each layer. Onyx was often used as the perfect foil for carved rock crystal or the 'drop dead red' of rubies in art deco designs. It is also popular in marcasite jewelry. Onyx is found worldwide. They are formed by the deposition of silica in gas cavities in lava.
