In jewelry design as in fashion, colors look crisper against a background of black and black and white always looks right. In fine jewelry, the black backdrop is often supplied by onyx, a chalcedony quartz with a fine texture and black color.
Some onyx also displays white bands or ribbons against a black background.
If the layers are even, this type of onyx can be carved into cameos. Onyx was very popular with the ancient Greeks and Romans. The name comes from the Greek word onux, which means 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.