onyx

A chalcedony that occurs in bands of different colors and is used as a gemstone, especially in cameos and intaglios.

A variety of quartz, closely allied to agate, characterized by a structure in parallel bands differing in color or in degree of translucency: in the better kinds the layers are sharply defined and the colors white with black, brown, or red.

An infiltration of pus between he layers of the cornea, resembling a nail.

In conchology: The piddock, Pholas dactylus.

A razor-shell; a bivalve of the family Solenidæ.

Deep, jet-black.

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.

Same as Mexican onyx.

A deep jet-black color.

a banded variety of marble or calcium carbonate resembling onyx. It is obtained from Mexico in various colors ranging from white to deep black.