onyx

Etymology

From Middle English onix (c. 1300), earlier oniche (c. 1250), from Old French oniche or onix, from Latin onyx, from Ancient Greek ὄνυξ (ónux, “onyx”). Doublet of unguis.

noun

1. (mineralogy) A banded variety of chalcedony, a cryptocrystalline form of quartz.
2. A jet-black color, named after the gemstone.
   onyx:
3. Any of various lycaenid butterflies of the genus Horaga.

adj

1. jet-black
   And the gold of that land is good: there is bdellium and the onyx stone. , Genesis, 2:12
   There was no moon, only stars set brilliantly in the soft black onyx of the sky : a black night and very silent on Cimiez ; and a black and silent prospect from the verandah […] 1922, Michael Arlen, “3/7/2”, in “Piracy”: A Romantic Chronicle of These Days