Legend/History:

Amethyst (SiO2) is a violet or purple variety of quartz often used in jewellery. The name comes from the Greek; a (not) and methuskein ("to intoxicate"), a reference to the belief that the stone protected its owner from intoxication; the ancient Greeks and Romans wore amethyst and made drinking goblets out of it in the belief that it would prevent drunkenness. Ranking members of the Roman Catholic Church traditionally wear rings set with a large amethyst as part of their office. Supposedly, when a drunken Dionysus was pursuing a maiden called Amethystos (which basically translates into "not drunken"), who refused his affections, she prayed to the gods to remain chaste. The goddesss Artemis granted the prayer, transforming her into a white stone; humbled by Amethystos' desire to remain chaste, Dionysus poured wine over the stone she had become as an offering, dying the crystals purple.

Attributes:

In the 20th century, the color of amethyst was attributed to the presence of manganese. However, since amethyst is capable of being greatly altered and even discharged by heat, the color was believed by some authorities to be from an organic source. Ferric thiocyanate was suggested, and sulfur was said to have been detected in the mineral.

On exposure to heat, amethyst generally becomes yellow, and much of the citrine, cairngorm, or yellow quartz of jewelry is said to be merely "burnt amethyst". Veins of amethystine quartz are apt to lose their color on the exposed outcrop.

Because it has a hardness of 7 on the Mohs scale, amethyst is treasured for its use in jewelry. However, it is still just 1/15 as hard as diamond.

Origin:

Amethyst was used as a gemstone by the ancient Egyptians and was largely employed in antiquity for intaglios. Amethyst is a widely distributed mineral, but fine, clear specimens that are suitable for cutting into gemstones are confined to comparatively few localities. Such amethyst crystals occur either in the cavities of mineral-veins in granitic rocks, or as a lining in agate geodes. A huge geode, or "amethyst-grotto", from near Santa Cruz in southern Brazil was exhibited at the Düsseldorf Exhibition of 1902. Many of the hollow agates of Brazil and Uruguay contain a crop of amethyst crystals in the interior. A lot of fine amethyst comes from Russia, especially from near Mursinka in the Ekaterinburg district, where it occurs in drusy cavities of granitic rocks. Brazil and many localities in India yield amethystas well; amethyst is also found in Sri Lanka, chiefly as pebbles.

Stone Energy Interpretation by Sylvia Rose-Johnson:

In general, Amethyst helps you "speak" to the Spirit. It is commonly a symbol of heavenly understanding, and of a pioneer in thought and action on the philosophical, religious, spiritual and material planes. Amethyst is the birthstone associated with February and is also associated with the Astrological signs of Pisces, Aries (especially the violet and purple variety), Aquarius, and Sagittarius.