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| Lazurite or Lapis lazuli from Russia |
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More Lazurite or Lapis-lazuli on ebay auction |
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Lazurite (Lapis Lazuli) Our LAZURITE came from Western-Siberian Region, Transbaikalia (Zabaykalye), Ust'-Orda Buriat Okrug, Lake Baikal Region, Sludyanka, Malaya Bystraya River museums.udel.edu Lazurite is relatively rare and occurs as a product of contact metamorphism of limestones. The best lazurite comes from the Firgamu mines of Afghanistan which have been producing lapis lazuli as long ago as the days of the Egyptian Pharaohs. At one time, lazurite was used as a pigment for altramarine paint, but now it is cheaper and easier to use synthetic pigments. wikipedia.org Lazurite is a product of contact metamorphism of limestone and typically is associated with calcite, pyroxenes, and pyrite. Other blue minerals such as the carbonate azurite and the phosphate lazulite may be confused with lazurite, but are easily distinguished with careful examination. Lazurite at one time was used as a synonym for azurite. Lazurite was first described in 1890 from the lapis lazuli district of Badakhshan, Afghanistan. The name is from the Persian lazward for blue.... galleries.com Lazurite is a popular but generally expensive mineral. Well-formed, deep blue crystals are rare and valuable. It is more commonly found massive and combined with other minerals into a rock called lapis lazuli. Lapis lazuli or lapis for short is mostly lazurite but commonly contains pyrite and calcite and some other minerals. The name means "blue rock" and is always a brilliant blue with violet or greenish tints. The rich blue color is due to the sulfur that is inherent in the structure of lazurite. Small crystals of pyrite are always present in lapis and their brassy yellow color is both attractive and diagnostic in distinguishing lapis from its also blue cousin - sodalite rock, which lacks pyrite. The calcite produces white streaks in the lapis and too much calcite will lower the value of the stone. Lapis lazuli has been mined for centuries from a locality still in use today in the remote mountain valley called Kokcha, Afghanistan. First mined 6000 years ago, the rock was transported to Egypt and present day Iraq and later to Europe where it was used in jewelry and for ornamental stone. Europeans even ground down the rock into an expensive powdered pigment for paints called "ultramarine". Today ultramarine is manufactured artificially. Although now not the only source of lapis, the source in Afghanistan still produces the finest quality material. Lazurite is a member of the feldspathoid group of minerals. Minerals whose chemistries are close to that of the alkali feldspars but are poor in silica (SiO2) content, are called feldspathoids. As a result or more correctly as a function of the fact, they are found in silica poor rocks containing other silica poor minerals and no quartz. If quartz were present when the melt was crystallizing, it would react with any feldspathoids and form a feldspar.. Localities that have feldspathoids are few. |
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