Old Testament Hebrew Lexical Dictionary
Strong's #306 - אַחְלָמָה
1) 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.
Jeff Brenner, Ancient Hebrew Research Center Used by permission of the author.
אַחְלָמָה f., Exodus 28:19, the name of a precious stone; LXX. Vulg. ἀμέθυστος. Josephus (in whom there appears however some confusion in the order of words), ἀχάτης. This word appears to be a verbal of the conj. Hiph. from חלם to dream, perhaps from [the superstitious idea of] its causing dreams to those who wore it. An idea of a similar kind gives its rise to the name ἀμέθυστος, because of its [having the supposed power of] keeping away drunkenness from the wearers; compare Braun. de Vestitu Sacerdot. Heb. (ii. 16).
the Seventh Week after Easter