A nail; claw; hoof, (Heb. sheheleth; Ex. 30:34), a Latin word applied to the operculum, i.e., the claw or nail of the strombus or wing-shell, a univalve common in the Red Sea. The opercula of these shell-fish when burned emit a strong odour “like castoreum.” This was an ingredient in the sacred incense.
Onycha
1 verse
Exodus
Exodus 30:34
And the LORD said unto Moses, Take unto thee sweet spices, stacte, and onycha, and galbanum; these sweet spices with pure frankincense: of each shall there be a like weight:
From Easton's Bible Dictionary
Matthew George Easton, 1897