Amethyst is the most valuable form of quartz, one of the world's most plentiful minerals. Amethyst is found in many locations in world, but the characteristics and quality of amethyst varies in interesting ways by location. For example, amethyst from South America is often found in large sizes while African amethyst is usually quite small. But the African amethyst can be highly saturated in color, making it popular with collectors.
The bulk of the world's supply of amethyst comes from South America, particularly Brazil and Uruguay. The most notable sources of amethyst in Brazil come from Minas Gerais, Rio Grande do Sul, Maraba and Bahia. Brazilian amethyst are typically found in vugs, or small cavities in rocks lined with crystals. Among the rock containing amethyst crystal in Brazil are large pockets formed by volcanic material. The crystals that are produced in these areas vary in color from pale to medium lilac but rarely reach a deep true dark purple of high saturation. The color in the crystals of these vugs is highly concentrated in the tips of the visible termination of each crystal.
Amethyst from Uruguay vary in saturation from a medium saturated to a deep highly saturated purple. Like in Brazil, amethyst crystals in Uruguay are found in volcanic vugs. The vugs of Uruguay are host rocks with a gray or brownish exterior and the larger vugs contain stalactites and other formations on which amethyst druses form. The entire crystal of each amethyst contains the coloration typical of this region.
Important deposits of amethyst are also found in North America. Thunder Bay, Ontario, is one of the major Canadian hosts of amethyst mines. The crystal druses, or the cluster of small crystals on a rock's surface, is hosted by archaic metamorphic rock. The color unique to Canadian mines includes a reddish inclusion slightly under the surface of each crystal.
The USA has a great diversity of amethyst deposits from Maine, Pennsylvania and North Carolina to Montana and Colorado. The color range of American amethyst is generally from medium to high in saturation and may include smoky or translucent versions of crystal. Amethyst of Maine and the Carolinas is usually dark with North Carolina amethyst having a bluish tint unique to that area. Colorado is known for having clusters of amethyst that have formed in cavities within sandstone.
Two main sources of amethyst from Mexico include mines located in Vera Cruz and Guerrero. Amethyst from Vera Cruz has a tendency to be of lighter shades and is typically clear. The crystals are very commonly triagonally terminated on both ends. The amethyst which comes from Guerrero is typically a deep and highly saturated dark purple. The crystal has a single, visible termination with a color saturated interior and transparent exterior.
Among the African countries that contain amethyst deposits are Zambia and Namibia. African. The amethyst druses of Africa contain small crystals of saturated color and outstanding clarity. As they occur naturally, the unrefined amethyst crystals are indistinct on the exterior and are commonly polished and carved.
Two of Europe's most notable sites for amethyst are found in Italy and Germany. Italy's deposits contain amethyst crystals of evenly distributed coloration. Crystals of pale hue and prismatic character are often large in size and can occur parallel in formation. German amethyst is often pale in color and is found coupled with other forms of crystal such as agates.
Amethyst deposits can also be found in other countries around the world such as: Bolivia, Argentina, Madagascar, India and Sri Lanka.
- First Published: August-28-2008
- Last Updated: March-01-2011
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