ὀψιανὸς

A. obsidian, Pliny's obsiana (neut. pl.), HN 36.196, cf. Peripl.M.Rubr. 5, Orph. L. 285, Cyran. 26: written ὀψειανόν PLeid.X. 36 B.; [ὀψ]ειανόν dub. in Supp.Epigr. 2.776 i 15 (Syria, iii A. D.). (Named from its discoverer Obsius, v. Plin. l. c.; obsidiana is f.l. ibid.; prob. α by nature.)