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. True,
black isn't normally the colour one associates with
fingernails. (Did Venus wear Vamp, perhaps?) 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.