Onyx was very popular with the ancient Greeks and Romans.
The name comes from the Greek word onux, meaning fingernail. The story is that one day 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.
True, black isn’t normally the color one associates with fingernails. But in Greek times, almost all colors of chalcedony from white to dark brown and black were called onyx. Today when we think of onyx we often preface the word with black to distinguish it from other varieties of onyx that come in white, reddish brown, brown and banded. Later, the Romans narrowed the term “onyx” to refer to black and dark brown colors only.