Source : Webster's Revised Unabridged Dictionary (1913)
Onyx \O"nyx\, n. [L., fr. Gr. ? a claw, finger nail, a veined
gem. See {Nail}, and cf. {Onycha}.] (Min.)
Chalcedony in parallel layers of different shades of color.
It is used for making cameos, the figure being cut in one
layer with the next as a ground.
{Onyx marble}, a banded variety of marble or calcium
carbonate resembling onyx. It is obtained from Mexico.
Source : WordNet®
onyx marble
n : a hard compact kind of calcite [syn: {alabaster}, {oriental
alabaster}, {Mexican onyx}]