Onyx is a translucent stone with pleasing and highly varied color and markings. It is closely related to marble. Both onyx and marble are composed of calcium carbonate, and both owe their origin to having been laid down in water. The name onyx came from the Greek word "onux" meaning "fingernail." The legend is Cupid cut the fingernails of Venus while she was sleeping. He left the clippings on the sand and they turned to stone. During Greek times, all colors of chalcedony were called onyx. It was highly prized in Rome for royal seals because it would not stick to the wax. Mexico's ancient Aztecs, Toltecs and Mayans assigned a holy character to onyx, possibly because it is visibly infused with light, and so had its place in their sun-worshipping religious beliefs. Onyx was called Tecali in Meshica, the Aztec tongue, literally meaning stone of the gods. Although onyx comes in a variety of colors, today it is most closely associated with the rich black hue that remains the most popular.