Amethyst

Hebrew root, "dream"; supposed to cause dreams to those who wore it. Greek, "protecting against drunkenness" Pliny says, because it approaches the color of wine without reaching it. The third jewel in the third row of the breast-plate of judgment. The twelfth of the precious foundation stones of the heavenly Jerusalem's walls (Revelation 21:20). A violet, or in the East a deep red, quartz; the eastern is a rare variety of the adamantine spar or corundum; the hardest substance next to the diamond, containing 90 per cent. alumine, with iron and silica. It loses color in the fire, and becomes like a diamond.