ONYX

Dictionary of Science, Literature and Art · 1854 · p. 22

A regularly banded agate, much prized for cameos, especially where the colours are very distinct and opposed. Any stone exhibiting layers of two or more colours strongly contrasted is called an onyx. O'nyx. In Surgery, an absce of the cornea of the eye; so called from its resemblance to the stone termed an onyx! [s. 864]