Strong's Definition
perhaps from 2492 (and thus dream-stone); a gem, probably the amethyst
KJV Usage: amethyst
STEPBible — Tyndale Abridged Hebrew Lexicon
אַחְלָ֑מָה (ach.la.mah) — amethyst. amethyst, a gem in the third row on the ephod, breastplate of judgment worn by the high priest. Transliteration of the Septuagint word. Identification is not certain but is a purple stone perhaps a corundum or red or brown jasper.
UBS Dictionary of Biblical Hebrew
UBS Dictionary of Biblical Hebrew © United Bible Societies, licensed CC BY-SA 4.0.
Brown-Driver-Briggs Hebrew Lexicon
אַחְלָ֑מָה n.f. perh. amethyst (etym. dub.) base