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Gems of America
Tourmaline (Part 2) Records indicate that from 1898 until 1914, the Himalaya was the world's largest producer of tourmaline. Furthermore, the records indicate that in 1904 production from the mine was at least 5.5 metric tons. In 1989, 84 years later, a single pocket in the mine produced more than 0.5 metric ton of tourmaline. The history of production from the mine is not one of steady continuous operation. The mine operated continuously from 1898 until 1914, after which it operated sporadically until 1952. At this time, it once again began continuous operations that lasted until 1964 when it returned to intermittent operation until 1977. Since then the mine has been in operation under the direction of Pala International. California tourmalines come in all colors except certain shades of blue and yellow. They also occur in bicolors, tricolors, and concentrically and laterally zoned combinations. Crystals vary in diameter from about 3 millimeters to as much as 125 millimeters, and vary in length from about 12 millimeters to as much as 250 millimeters. Because of the large size of the crystals available, some large stones have been cut from California tourmaline. A 400-carat pink-red stone has been cut, as well as a flawless 75 carat green to pink bicolor and flawless 30- to 40 carat green to colorless to pink tricolored stones. California deposits should continue to produce quantities of faceting, carving, and cabochon grade, as well as specimen-grade tourmalines for some time into the future. In late 1992, a new deposit of tourmaline was discovered in Riverside County that could result in greater production over even a longer period of time. Maine.--Tourmaline was the first gemstone mined in the United States by miners other than prehistoric man or Native Americans. Tourmaline mining began at Mount Mica, ME, in 1822 and, with starts and stops, has continued to the present. In 1992, operations at Mount Mica produced both gem-quality and mineral specimen tourmaline. Over the years, mining operations on Mount Mica produced hundreds of kilograms of tourmaline. Museums and private collections around the world contain outstanding examples of tourmaline from the deposit. The largest reported crystal from the site apparently is one that is 39.4 centimeters long, 17.8 centimeters wide, and weighs about 14.3 kilograms. Apparently, a flawless, blue-green 256-carat stone is the largest cut stone from Mount Mica. Mount Mica may have been the first tourmaline producer in Maine, but it is by no means the largest. Newry Hill, a spur off Plumbago Mountain, or more specifically the Dunton Mine on Newry Hill, is the most prolific tourmaline producer in Maine. Since its discovery in 1898, production from the mine has exceeded thousands of kilograms of high-quality tourmaline. The mines ability to yield large quantities of quality tourmaline was clearly demonstrated by Plumbago Mining Corp. The company reported that from October 1972 until the Fall of 1974, it produced more than one metric ton of fine-quality tourmaline. Other mines and quarries in a three county area produce gem- and specimen-grade tourmalines. The level and type of activities at each mine or quarry vary from year to year. Currently, most of them are open to hobbyist or professional collectors for a fee or with the owners permission. Maine tourmalines come in a wide variation of colors, deep grass green to light green to yellow-green to blue green. They are also found in all shades of red, from pink to deep red, and blue-green to light blue to deep blue, and as colorless crystals. The State's mines also produce bicolors and watermelon crystals. The colors can be very fine and some believe that Maine tourmalines set the standard for non-chrome green tourmaline. Article source: U.S.G. S.
Previous articles on Gems of America: Gems of America : U.S. Pearls (Part1). / Gems of America : U.S. Pearls (Part2). Gems of America : Chalcedony (Part1). / Gems of America : Chalcedony (Part2). Gems of America : Chalcedony (Part3). / Gems of America : Opal (Part 1). Gems of America : Opal (Part 2). / Gems of America - Quartz (part 1). Gems of America - Quartz (part 2). / Gems of America - Feldspar (Part 1) Gems of America - Feldspar (Part 2). / Gems of America - Sapphire (Part 1) Gems of America - Sapphire (Part 2). / Gems of America - Tourmaline (Part 1) Your Feedback
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