onyx
nounA 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.
