onyx /ˈɒnɪks/noun 3adjective 1forms 1 noun3 •A banded variety of chalcedony, a cryptocrystalline form of quartz.People talk about using marble in the bathrooms. Marble wasn't good enough for use—we have onyx! — 2023 •A jet-black color, named after the gemstone. •Any of various lycaenid butterflies of the genus Horaga. adjective1 •Jet-black; often, glossily so. formsonyxes
