Amethyst Gemstone History
A stone for the masses, amethyst has adorned many a royal crown, and yet has remained affordable enough to make its way into everyday jewelry in recent centuries. The birthstone for February, the 6th wedding anniversary and the sign of Pieces, amethyst holds significant symbolism and history.
Amethyst History
Amethyst was found and used as far back as 2000 BC, and was once as expensive and as revered as rubies and emeralds. It was not only set into royal jewelry, but was often incorporated into rings for clergy and religious leaders. Like many stones, when a larger mining deposit is discovered it changes everything. For amethyst, it was a Brazilian deposit in the 19th century that made the stone at once plentiful and more affordable. Despite its plentiful reserves, it has remained a beloved stone even at the highest echelons. One example is the famed Cartier amethyst and turquoise bib necklace, with a heart shaped amethyst centerpiece, that was commissioned by the Duchess of Windsor. It ultimately sold at auction in the 1980‚ for close to $700,000. Another is the gorgeous Edwardian Morris Amethyst brooch, with a bewildering 96 carat heart shaped amethyst surrounded by diamonds. 
Art Deco 10k green, rose and yellow gold amethyst cabochon ring from Stacey Fay Designs (sold).
Amethyst Symbolism
In spite of its intoxicating color, amethyst was believed by the Greeks to ward off intoxication ‚the word comes from the ancient Greek word Amethystos, meaning remedy against drunkeness. Its wine-like color is associated with Bacchus, the God of wine, and was thought by many cultures over the centuries to bring the opposite effect, clearheadedness, and quick wit. Leonardo DeVinci concurred, saying the stone heightened intelligence and warded off evil thoughts. 
A vintage H. Stern gold "sputnik" ring with amethyst centerpiece, surrounded by a variety of other stones.
It also has romantic connotations - St. Valentine is fabled to have worn an amethyst intaglio ring with the image of cupid and it is known as the gemstone signifying true love and fidelity. 
ca. 1820 --- Portrait of Josef Walland by Giuseppe Tominz --- Image by © Elio Ciol/Corbis.
Amethyst was linked by early Christians to Christ, and the purification of spirit. In fact, its color was likened to the wounds and suffering of Christ and therefore associated with the healing of wounds, and in many cultures, used as protective amulets.To this day it is a spiritual stone, used in the balancing of chakras.
Amethyst Characteristics
A lovely and dainty pair of gold amethyst stud earrings (sold, Stacey Fay Designs).
Amethyst is actually a type of quartz, and the most desired one with its color. It can come in a variety of hues, from a very faint purple to a vibrant raspberry, and can be muddier or vivid. Many amethysts consist of what is known as color zoning‚ or sections of lighter and darker color within them. The most valuable amethysts are those of a deep purple and no zoning, or a reddish purple, and the most valuable of all is the exceptionally rare Russian or Siberian amethyst.
Amethysts can, and often are, cut in a variety of shapes, including even novelty animal shapes, and come in a wide variety of carat sizes as well. The price does not dramatically increase with the size and carat weight of the stone. Amethyst is fairly hardy and can be used in rings and other every day pieces, but with a Mohs hardness of 7 it will show some wear over time and may need repolishing after many years of wear. You can clean your amethyst jewelry with warm, soapy water.
References: www.gia.edu www.americangemsociety.org www.gemsociety.org