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
Onyx
A hail; claw; hoof, (Heb. shoham), a precious stone adorning the breast-plate of the high priest and the shoulders of the ephod (Ex. 28:9-12, 20; 35:27; Job 28:16; Ezek. 28:13). It was found in the land of Havilah (Gen. 2:12). The LXX. translates the Hebrew word by smaragdos, an emerald. Some think that the sardonyx is meant. But the onyx differs from the sardonyx in this, that while the latter has two layers (black and white) the former has three (black, white, and red).
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.