Onyx stones. — The Hebrew shoham is rendered here by “sard” (LXX.), “sardonyx” (Vulg. And Josephus), and “beryl” (Rosenmüller and others). In Job 28:16, the same word is rendered by the LXX. “onyx.” There is thus considerable doubt what stone is meant. Only three such stones seem to have been required as offerings, one for the high priest’s breast-plate (Exodus 28:20), and two for the shoulder- pieces of the ephod (Exodus 28:9-12).
Stones to be set in the ephod and in the breastplate. — Heb., stones of insertion for the ephod and for the breast-plate. The stones of the ephod were two only, both probably either onyx or sardonyx; those of the breast-plate were twelve in number, all different (Exodus 28:17-20).