Diamond occurs in the Auth. Vers. as the translation of two Heb. words. SEE GEM.
1. יִהֲלם (yahalom´, so called from beating, with allusion to its hardness), a precious gem, placed sixth in the breastplate of the high-priest, with the name of Naphtali carved on it (Ex 28:18; Ex 39:11), and mentioned in Eze 28:13; among the precious stones of the king of Tyre. The Sept. and Vulg. understand by it the jasper; several of the ancient versions render it by onyx, which is not improbable; still others by adamant, which is less likely. There is much reason to doubt whether the diamond vas known in the time of Moses (see below). Our translation "diamond" is derived from Aben Ezra, and is defended by Braun (Vest. Sacerd. 2:13). Kalisch (on Exodus p. 536) says "perhaps emerald." SEE ONYX.
2. שָׁמַיר (shamir´, a sharp point; hence often a brier), a precious stone, named in Jer 17:1; Eze 3:9; Zec 7:12. The Sept. in Jeremiah, and the Vulg. in all the passages, take it for the diamond. The signification of the word (from שָׁמִר, to pierce) countenances this interpretation, the diamond being, for its hardness, used in perforating and cutting other minerals. Indeed, this use of the shamir is distinctly alluded to in the passage in Jeremiah, where the stylus pointed with it is distinguished from one of iron (comp. Pliny, Hist. Nat. 37:15). The two other passages also favor this view by using it figuratively to express the hardness and obduracy of the Israelites. Our version has "diamond" in Jer 17:1, and "adamant" in the other texts. Bochart, however (Hieroz. 3, 843 sq.), rejects the usual explanation, and, comparing the word shamir with the Greek σμῖρις or σμῦρις, conceives it to mean "emery." This is a calcined iron mixed with siliceous earth, occurring in livid scales of such hardness that in ancient times, as at present, it was used for polishing and engraving precious stones, diamonds excepted (Hoffmann, Mineral. 1:561 sq.). Bohlen suggests an Indian origin of the word, and compares asmirla, stone which eats, spoken of gems, iron, etc. from their hardness. Rosenmüller is in favor of the diamond in his Scholia, but in his Alterthumskunde he takes up Bochart's notion, and urges that if the Hebrews had been acquainted with the diamond, and the manner of working it, we should doubtless have found it among the stones of the high-priest's breastplate; and that, as the shamir was not one of the stones thus employed, therefore it was not the diamond. But to this it may be replied that it was perhaps not used because it could not be engraved on, or was possibly not introduced until a later period. The argument drawn from the rarity of the word in the Old Testament is of little weight, and there is no necessity for seeking an Oriental origin of the word σμῦρις, or ground for considering it identical with shamir, as it may easily be traced from the Greek itself (see Passow, s.v.; Eichhorn, De Gemmis Sculpt. Hebr.). For an account of the diamond of the ancients, see Moore's Ancient Mineralogy, p. 143-145. SEE ADAMANT.
The diamond is the hardest and most valuable of the precious stones, and for many ages was considered indestructible by fire or any other means; modern chemistry, however, has proved that at a heat rather below that required to melt silver it is gradually dissipated or burned. It is, in fact, nothing but pure carbon, but in a more highly crystallized state than coal. In former times, all the diamonds that were known were brought from different parts of India, particularly from the famous mine of Golconda, near Hyderabad, the present capital of the Deccan, in Hindostan; the islands of Molucca and Borneo have also produced many valuable stones. The diamond mines of Golconda are now so far exhausted as to be considered not worth the expense of working, and the diamonds which are brought to Europe come chiefly from Brazil. They are always found in an alluvial soil, generally gravel, resting on granite, and not imbedded in any other substance, but appear like small pebbles, with the surface flattened in many parts.