(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. (Heb. yahalom), a gem crystallized carbon, the most valued and brilliant of precious stones, remarkable for its hardness, the third precious stone in the second row on the breastplate of the high priest, (Exodus 28:18; 39:11) and mentioned by Ezekiel, (Ezekiel 28:13) among the precious stones of the king of Tyre. Some suppose yahalom to be the "emerald." Respecting shamir, which is translated "Diamond" in (Jeremiah 17:1) see under [433]Adamant.
Diamond