Rock Type. Igneous , Sedimentary , Metamorphic. Popularity Prevalence Demand Potassium Feldspar. Name used to describe the minerals belonging to the potassium feldspar group , specifically Orthoclase , Microcline , and Sanidine. Adularia - White or colorless, transparent to translucent variety of Orthoclase or Sanidine. Moonstone - Form of feldspar that displays a color sheen known as adularescence. Noble Orthoclase - Describes a transparent, yellow variety of Orthoclase from Madagascar.
Microcline , Sanidine. Orthoclase is industrially important in the manufacture of glass and ceramics. Orthoclase crystals and twin s provide information on the formation of minerals and environment al factors. Well shaped crystals and twins are highly sought after by mineral collectors, and the Moonstone variety is used as a gemstone. For additional information, see the gemstone section on Orthoclase and Moonstone.
Orthoclase is one of the most common minerals, and is found worldwide. Only a select few localities are mentioned. Some of the best crystals come from Baveno, Piedmont, Italy, especially the famous Baveno twins. Light blue crystals came from the the Lake Baikal area in Russia, and large masses from Mt. Kilimanjaro, Tanzania. Transparent gemmy yellow crystals that have recently become very popular come from a pegmatite in Madagascar, at Itrongay, Tulear Province.
In the U. Orthoclase has also come from the French Creek mine, St. Peters, Chester Co. Sanidine - Indistinguishable without complex methods. Sanidine, however, is never opaque. Microcline - Indistinguishable without complex methods. However, Microcline can have a deep green color that Orthoclase cannot achieve. Plagioclase Feldspar s - May exhibit striation s on twinned crystal surfaces, otherwise difficult to distinguish.
Spodumene - Has a splintery fracture. Calcite - much softer 3. Have a question about Orthoclase? To sponsor this page, click here. Amazon Supply Store. Hammers, Chisels, Loupes, Cotton-filled boxes, etc. Recommended Reading. Our Recommended Book Selection at Amazon. Support Minerals. Financial Donations and Collection Acquisitions. Mineralogists classify the best of these microcline orthoclase as the semiprecious stone amazonite. In Madagascar, jewelers and gemologists cut and facet rare transparent orthoclase into jewelry-grade gemstones.
Mines from India to Australia and in Brazil produce moonstone. Industrial-grade orthoclase forms in igneous rock worldwide. Mining companies grind orthoclase that is not distinctive for its color, clarity or other unique qualities into different industrial grades from powder to coarse gravel. Several industries make use of this raw orthoclase as binding agents in porcelain, china and earthenware products, as an ingredient in glass sand and as an abrasive in different commercial cleaning products.
It is also common in other ceramic products such as wall and floor tile or dental ceramics, and is a common ingredient in ceramic glaze. Orthoclase that is notable for its clarity and beauty and is considered to be gemstone quality. Several different semi-precious gems are forms of orthoclase, including moonstone, beryl and faceted orthoclase. In Madagascar, jewelers cut clear or champagne-colored orthoclase into faceted gemstone to set in jewelry; it looks similar to tourmaline.
Gemologists generally classify opalescent orthoclase as moonstone, which jewelers cut into round cabochons, polishing the cut stone to bring out the shimmering colors.
0コメント