Strong’s Greek
G271 — amethustos
The entry below is Strong’s own definition (1890, public domain), and every verse where the word occurs.
ἀμέθυστος
amethustos — pronounced am-eth'-oos-tos
from 1 (as a negative particle) and a derivative of 3184; the "amethyst" (supposed to prevent intoxication):--amethyst. see GREEK for 1 see GREEK for 3184
1 occurrence in the KJV.
Revelation 21:20
The fifth, sardonyx; the sixth, sardius; the seventh, chrysolyte; the eighth, beryl; the ninth, a topaz; the tenth, a chrysoprasus; the eleventh, a jacinth; the twelfth, an amethyst.