King James Bible Dictionary

One of the precious stones in the breastplate of the high priest (Exodus 28:19; 39:12), and in the foundation of the New Jerusalem (Revelation 21:20). The ancients thought that this stone had the power of dispelling drunkenness in all who wore or touched it, and hence its Greek name formed from a_, "privative," and _methuo, "to get drunk." Its Jewish name, ahlamah', was derived by the rabbins from the Hebrew word halam, "to dream," from its supposed power of causing the wearer to dream.

It is a pale-blue crystallized quartz, varying to a dark purple blue. It is found in Persia and India, also in different parts of Europe.

A precious stone.
Exodus 28:19; Exodus 39:12; Revelation 21:20

(Heb. achlamah) a subspecies of quartz of a bluish-violet color. Mention is made of this precious stone, which formed the third in the third row of the high priestly breastplate, in (Exodus 28:19; 39:12) It occurs also in (Revelation 21:20)

AM'ETHYST, noun [Latin amethystus; Gr. which the Greeks supposed to be formed from a neg. and to inebriate, from some supposed quality in the stone of resisting intoxication. Plin. 37.9, mentions an opinion that it takes its name from its color approaching that of wine, but not reaching it.]

A sub-species of quartz, of a violet blue color, of different degrees of intensity. It generally occurs crystallized in hexahedral prisms or pyramids; also in rolled fragments, composed of imperfect prismatic crystals. Its fracture is conchoidal or splintery. It is wrought into various articles of jewelry.

AM'ETHYST, in heraldry, signifies a purple color. It is the same, in a nobelman's escutcheon, as purpure, in a gentleman's and mercury, in that of a prince.

AMETHYST'INE, adjective Pertaining to or resembling amethyst; anciently applied to a garment of the color of amethyst, as distinguished from the Tyrian and hyacinthine purple.