a transparent gem of a purple colour, which seems composed of a strong blue and a deep red; and, according as either of these prevails, affording different tinges of purple, sometimes approaching to violet, and sometimes even fading to a pale rose colour. Though the amethyst is generally of a purple colour, it is nevertheless sometimes found naturally colourless, and may at any time be easily made so by putting it into the fire; in which pellucid or colourless state it so resembles the diamond, that its want of hardness seems the best way of distinguishing it. Some derive the name amethyst from its colour, which resembles wine mixed with water; while others, with more probability, think it got its name from its supposed virtue of preventing drunkenness,—an opinion which, however imaginary, prevailed to that degree among the ancients, that it was usual for great drinkers to wear it about their necks. Be this as it may, the amethyst is scarcely inferior to any of the gems in the beauty of its colour. The common amethyst is a variety of quartz; the oriental amethyst is a variety of spinelle. Its most common form is a six-sided prism, terminated by a flat and short pyramid of the same number of sides. The amethyst is found in the East and West Indies, Siberia, and in every part of Europe; the oriental being so hard and bright as to equal any of the coloured gems in value. The common amethysts, however, fall infinitely short of these; all the European ones, and not a few of those brought from the East and West Indies, are a mere variety of rock crystal.

Counterfeit or Factitious AMETHYST. Spars and crystals tinged red and yellow, &c., are sold for amethysts. The false ones come from Germany, are tinged by vapours in the mines, and contain lead and manganese.

Amethysts may be counterfeited by glass, to which the proper colour or stain is given. There were fine ones made in France about the year 1690, which may even impose on connoisseurs, unless the stone be taken out of the collet.

in Heraldry, a term for the purple colour in the coat of a nobleman, in use with those who blazon with precious stones instead of metals and colours. This, in a gentleman's escutcheon, is called Purpure; and in those of sovereign princes, Mercury.