Amethyst from uruguay direct. Citrine is the yellow to brownish-red variety of the mineral Quartz. Amethyst Amethyst, the purple variety, is the most popular and valuable Quartz gemstone. In some Amethyst deposits, the Amethyst has been partially or fully changed over to yellow . African Amethyst - The Mineral and Gemstone Kingdom Amethyst originating from the continent of Africa. Green Amethyst - The Mineral and Gemstone Kingdom Light green gem form of Quartz that is artificially colored by heat-treating certain types of Amethyst. See the Amethyst gemstone page for more details. Amethyst ranges from light to dark purple. Amethyst is the purple variety of the mineral Quartz, and is its most famous and valuable gem variety. There is also a transparent sky blue form of Quartz crystals, as well as a wildly iridescent type that are synthetically colored by irradiation of gold. Most Citrine is formed by heat treating purple Amethyst. Quartz also contains other gemstones such as Citrine, Rose Quartz, and Smoky Quartz. When used as a Amethyst from Rhode Island from Diamond Hill, Ashaway, south of Hopkinton, Washington County, Rhode Island The Mineral and Gemstone Kingdom is a free informational and educational guide to rocks, minerals, gemstones, and jewelry. In some Amethyst deposits, the Amethyst has been partially or fully changed over to yellow Amethyst is the purple variety of the mineral Quartz, and is its most famous and valuable gem variety. This site has been providing detailed information and photos of hundreds of mineral and gemstone since 1997 and is one of the leading education resources on minerals and gemstones. The color of Amethyst is most often caused by iron impurities, though it can also be colored by natural radiation exposure. This term in the gem trade usually applies to deeply colored or darker Amethyst. Also known as "Prasiolite". It is a widely used as a gemstone, and after Amethyst it is the most popular Quartz gem. Citrine may also be produced by heat-treating Smoky Quartz from certain localities. Citrine Citrine is the yellow, orange, or reddish-brown variety of Quartz. It is usually colored by heat treatment of Amethyst or Smoky Quartz. The color of some Amethyst specimens from certain localities slowly fade upon prolonged exposure to light. It is the purple variety of the mineral Quartz, and its most valuable and prized variety. Brazilian Amethyst - The Mineral and Gemstone Kingdom Amethyst originating from Brazil. Much Amethyst is also heat treated to intensify color, and a green transparent form known as "Green Amethyst" or "Prasiolite" is formed by heat treating certain types of Amethyst. This terms is also sometimes used in the gem trade to refer to any South American Amethyst. Its name derives from the Greek "amethystos", which means "not drunken", as Amethyst in antiquity was thought to ward off drunkenness. Amethyst is sometimes heat treated to deepen the color, or to transform it into Amethyst is a well known mineral and gemstone. buvbz ijjsx olpi pwl dia idkeh mqed azqvtc zaodws gucf