Amethyst

One of the precious stones in the breastplate of the high priest (Ex. 28:19; 39:12), and in the foundation of the New Jerusalem (Rev. 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.

אחלמה, Exod. xxviii, 19; and xxix, 12; and once in the New Testament, Rev. XXI, 20, ἀμέθυϛος. A transparent gem, of a colour which seems composed of a strong blue and deep red; and, according as either prevails, affords different tinges of purple, sometimes approaching to violet, and sometimes even fading to a rose colour. The stone called amethyst by the ancients was evidently the same with that now generally known by this name; which is far from being the case with regard to some other gems. The oriental is the hardest, scarcest, and most valuable. It was the ninth stone in the pectoral of the high priest, and is mentioned as the twelfth in the foundations of the New Jerusalem.