Extended Strong's Greek Lexicon (Abbott-Smith based)
amethyst
Usage: ἀμέθυστος, -ου, ἡ (accusative to Plut., ἀ- μεθύω, being regarded as an antidote against drunkenness) [in LXX: Exo.28:19 36:19 39:12 Eze.28:13 * ;] amethyst, a purple quartz: Rev.21:20.† (AS)