Apparently from the same as shachal through some obscure idea, perhaps that of peeling off by concussion of sound; a scale or shell, i.e. The aromatic mussel. -- onycha.
see HEBREW shachal
H7827. shecheleth
שְׁחֵ֫לֶת noun feminine an ingredient of the holy incense, + חֶלְבְּנָה נָטָף,, Exodus 30:34; ᵑ9 ᵐ5 ὄνυξ, onyx (whence AV onycha), i.e. unguis odoratus, the operculum, or closing-flap, of certain molluscs, with pungent odour whenburnt, see Thes1388f. Di Shipley-CookEncy. Bib. ONYCHA; so most; KG JacobZMG xliii (1889), 354 proposes amber.
שׁחן (√ of following; compare Arabic be hot, then inflamed; Aramaic שְׁחַן, be warm, heat).