Dictionary
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.
Dictionary
Beryl
The rendering in the Authorized Version of the Hebrew word tarshish, a precious stone; probably so called as being brought from Tarshish. It was one of the stones on the breastplate of the high priest (Ex. 28:20; R.V. marg., "chalcedony;" 39:13). The colour of the wheels in Ezekiel's vision was as the colour of a beryl stone (1:16; 10:9; R.V., "stone of Tarshish"). It is mentioned in Cant. 5:14; Dan. 10:6; Rev. 21:20. In Ezek. 28:13 the LXX. render the word by "chrysolite," which the Jewish historian Josephus regards as its proper translation. This also is the rendering given in the Authorized Version in the margin. That was a gold-coloured gem, the topaz of ancient authors.
Dictionary
Diamond
(1.) A precious gem (Heb. yahalom', in allusion to its hardness), otherwise unknown, the sixth, i.e., the third in the second row, in the breastplate of the high priest, with the name of Naphtali engraven on it (Ex. 28:18; 39:11; R.V. marg., "sardonyx.") (2.) A precious stone (Heb. shamir', a sharp point) mentioned in Jer. 17:1. From its hardness it was used for cutting and perforating other minerals. It is rendered "adamant" (q.v.) in Ezek. 3:9, Zech. 7:12. It is the hardest and most valuable of precious stones.