Amethystus, amethysti, m. g. Plin. A stone called an Amethylt of colour purple: but the more rose colur the better. Also a kinde of grapes, and a certaine hearbe.Amethystus purpureus.Ouid.
Lewis and Short: Latin dictionary
ămĕthystus, i, f., = a)me/qustos. I.The amethyst, a precious stone of violet-blue color, Plin. 37, 9, 40, 121 sqq.; Vulg. Exod. 28, 19; ib. Apoc. 21, 20.—II.A kind of vine, Col. 3, 2, 24; cf. Plin. 14, 2, 4, 31.