Quartz

The Hebrew stone יַהֲלֹם, traditionally rendered "diamond," appears in scripture as one of the twelve gemstones set in the high priest's breastplate and among the precious stones covering the king of Tyre in Eden's garden. The precise identification is uncertain, but quartz (including rock crystal, milky quartz, and amethyst) fits the etymological and archaeological evidence. (The engraving-point called "diamond" in older translations is emery — a different stone, treated in the Emery article.)

A Stone in the Breastplate

The quartz is named in the second of the four rows of stones set in the breastplate of judgment. In the original instructions for Aaron's vesture, the rows are laid out by name: "And you will set in it settings of stones, four rows of stones: a row of sardius, topaz, and carbuncle will be the first row; and the second row an emerald, a sapphire, and a quartz; and the third row a jacinth, an agate, and an amethyst; and the fourth row a beryl, and an onyx, and a jasper: they will be enclosed in gold in their settings" (Ex 28:17-20). When Bezalel and his craftsmen carry out the instructions, the same arrangement is reproduced verbatim, with the quartz again standing as the third stone of the second row: "And they set in it four rows of stones. A row of sardius, topaz, and carbuncle was the first row; and the second row, an emerald, a sapphire, and a quartz; and the third row, a jacinth, an agate, and an amethyst; and the fourth row, a beryl, an onyx, and a jaspar: they were enclosed in enclosings of gold in their settings" (Ex 39:10-13).

Among the Stones of Eden

In the lament over the king of Tyre, the quartz reappears in a catalogue of gems that form the covering of the figure who once dwelt in Eden's garden. Several of the breastplate stones are named together, the quartz among them: "You were in Eden, the garden of God; every precious stone was your covering, the sardius, the topaz, and the quartz, the beryl, the onyx, and the jasper, the sapphire, the emerald, and the carbuncle, and gold: the workmanship of your tabrets and of your pipes was in you; in the day that you were created they were prepared" (Eze 28:13). The arrangement differs from the breastplate, but the cluster — sardius, topaz, quartz, beryl, onyx, jasper, sapphire, emerald, carbuncle — overlaps with it almost entirely.