Strong's #271: amethustos (pronounced am-eth'-oos-tos)
from 1 (as a negative particle) and a derivative of 3184; the "amethyst" (supposed to prevent intoxication):--amethyst.
Thayer's Greek Lexicon:
̓́
amethustos
1) amethyst, a precious stone of a violet and purple colour
Part of Speech: noun feminine
Relation: from G1 (as a negative particle) and a derivative of G3184
Usage:
This word is used 1 times:
Revelation 21:20: "a jacinth; the twelfth, an amethyst."