Onycha
Onycha , noun
[New Latin, from Latin onyx, -ychis, onyx, also, a kind of mussel, Greek {not transcribed}, {not transcribed}. See Onyx.]
1.
An ingredient of the Mosaic incense, probably the operculum of some kind of strombus. — Ex. xxx. 34
2.
The precious stone called onyx. [Rare]