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Lunar Ferroan Anorthosite #60025 (Plagioclase Feldspar). Collected by Apollo 16 from the Lunar Highlands near Descartes Crater. This sample is currently on display at the National Museum of Natural History in Washington, DC. United States (Unknown scale)
Lunar Ferroan Anorthosite #60025 (Plagioclase Feldspar). Anorthosite (æˈnɔrθəsaɪt/ /ə- is a Phaneritic, Intrusive Igneous rock characterized by a predominance of Plagioclase Feldspar Plagioclase is a very important series of tectosilicate Minerals within the Feldspar family Collected by Apollo 16 from the Lunar Highlands near Descartes Crater. The geology of the Moon (sometimes called selenology, although the latter term can refer more generally to "lunar Descartes is a heavily-worn lunar crater that is located in the rugged south-central highlands of the Moon. This sample is currently on display at the National Museum of Natural History in Washington, DC. The National Museum of Natural History is a Natural history Museum administered by the Smithsonian Institution, located on the National Washington DC ( formally the District of Columbia and commonly referred to as Washington, the District, or simply D United States (Unknown scale)

Feldspar is the name of a group of rock-forming minerals which make up as much as 60% of the Earth's crust. The United States of America —commonly referred to as the A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition a highly ordered atomic structure and specific EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 In Geology, a crust is the outermost solid shell of a planet or moon [1]

Feldspars crystallize from magma in both intrusive and extrusive igneous rocks, and they can also occur as compact minerals, as veins, and are also present in many types of metamorphic rock. In Materials science, a crystal is a Solid in which the constituent Atoms Molecules or Ions are packed in a regularly ordered repeating Magma (Plurals magmas and magmata) is molten rock that sometimes forms beneath the surface of the Earth (or any other Terrestrial planet In Geology, an intrusion is a body of Igneous rock that has Crystallized from molten Magma below the surface of the Earth. Extrusive refers to the mode of Igneous Volcanic rock formation in which hot Magma from inside the Earth flows out (extrudes onto the surface Igneous rocks (etymology from Latin ignis, fire are rocks formed by solidification of cooled Magma (molten rock Metamorphic rock is the result of the transformation of an existing rock type the protolith, in a process called Metamorphism, which means "change [2] Rock formed entirely of plagioclase feldspar (see below) is known as anorthosite. Plagioclase is a very important series of tectosilicate Minerals within the Feldspar family Anorthosite (æˈnɔrθəsaɪt/ /ə- is a Phaneritic, Intrusive Igneous rock characterized by a predominance of Plagioclase Feldspar [3] Feldspars are also found in many types of sedimentary rock. Sedimentary rock is one of the three main rock types (the others being igneous and Metamorphic rock) [4]

Contents

Etymology

Feldspar is derived from the German Feld, field, and Spat, a rock that does not contain ore. The German language (de ''Deutsch'') is a West Germanic language and one of the world's major languages. In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere An ore is a volume of rock containing components or Minerals in a mode of occurrence that renders it valuable for mining "Feldspathic" refers to materials that contain feldspar. The alternative spelling, felspar, has now largely fallen out of use. [5]

Compositions

Feldspar
Feldspar
Alkali feldspar perthite (7cm long X 3cm width)
Alkali feldspar perthite (7cm long X 3cm width)

This group of minerals consists of framework or tectosilicates. The silicate minerals make up the largest and most important class of rock-forming Minerals They are classified based on the structure of their silicate Ion group Compositions of major elements in common feldspars can be expressed in terms of three endmembers:

K-feldspar endmember KAlSi3O8[1]

Albite endmember NaAlSi3O8[1]

Anorthite endmember CaAl2Si2O8[1]

Solid solutions between K-feldspar and albite are called alkali feldspar. An endmember in Mineralogy is a Mineral that is at the extreme end of a mineral series in terms of purity Physical properties Orthoclase crystallizes in the Monoclinic crystal system Potassium (pəˈtæsiəm is a Chemical element. It has the symbol K (kalium from qalīy Atomic number 19 and Atomic mass 39 WikipediaNaming Silicon (ˈsɪlɪkən or /ˈsɪlɪkɒn/ silicium is the Chemical element that has the symbol Si and Atomic number 14 Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Albite is a plagioclase Feldspar Mineral. It is the sodium endmember of the Plagioclase Solid solution series Sodium (ˈsoʊdiəm is an element which has the symbol Na( Latin natrium, from Arabic natrun) atomic number 11 atomic mass 22 WikipediaNaming Silicon (ˈsɪlɪkən or /ˈsɪlɪkɒn/ silicium is the Chemical element that has the symbol Si and Atomic number 14 Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Anorthite is a compositional variety of Plagioclase Feldspar. Calcium (ˈkælsiəm is the Chemical element with the symbol Ca and Atomic number 20 WikipediaNaming Silicon (ˈsɪlɪkən or /ˈsɪlɪkɒn/ silicium is the Chemical element that has the symbol Si and Atomic number 14 Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the A solid solution is a Solid - state Solution of one or more solutes in a Solvent. The alkali feldspar group are those Feldspar Minerals rich in the Alkali elements Potassium and Sodium. [1] Solid solutions between albite and anorthite are called plagioclase[1], or more properly plagioclase feldspar. Plagioclase is a very important series of tectosilicate Minerals within the Feldspar family Only limited solid solution occurs between K-feldspar and anorthite, and in the two other solid solutions, immiscibility occurs at temperatures common in the crust of the earth. Miscibility is a term commonly used in Chemistry that refers to the property of Liquids to mix in all proportions forming a Homogeneous Solution Albite is considered both a plagioclase and alkali feldspar. In addition to albite, barium feldspars are also considered both alkali and plagioclase feldspars. Barium feldspars form as potassium is replaced by barium.


The alkali feldspars are as follows:

Sanidine is stable at the highest temperatures, and microcline at the lowest. The alkali feldspar group are those Feldspar Minerals rich in the Alkali elements Potassium and Sodium. Physical properties Orthoclase crystallizes in the Monoclinic crystal system In Crystallography, the monoclinic Crystal system is one of the 7 lattice Point groups A crystal system is described by three vectors. Sanidine is the high temperature form of potassium Feldspar (KNa(SiAl4O8 See also List of minerals In Crystallography, the triclinic Crystal system is one of the 7 lattice Point groups A crystal system is described by three basis vectors See also List of minerals [7][6] Perthite is a typical texture in alkali feldspar, due to exsolution of contrasting alkali feldspar compositions during cooling of an intermediate composition. Perthite is used to describe an intergrowth of two Feldspars a host grain of Potassium -rich Alkali feldspar (near K-feldspar KAlSi3O8 A solid solution is a Solid - state Solution of one or more solutes in a Solvent. The perthitic textures in the alkali feldspars of many granites can be seen with the naked eye. Granite (ˈɡrænɪt is a common and widely occurring type of intrusive, Felsic, igneous rock. [9] Microperthitic textures in crystals are visible using a light microscope, whereas cryptoperthitic textures can only be seen using an electron microscope.


Labradorite
Labradorite

The plagioclase feldspars are triclinic. The plagioclase series follows (with percent anorthite in parentheses):

Intermediate compositions of plagioclase feldspar also may exsolve to two feldspars of contrasting composition during cooling, but diffusion is much slower than in alkali feldspar, and the resulting two-feldspar intergrowths typically are too fine-grained to be visible with optical microscopes. Albite is a plagioclase Feldspar Mineral. It is the sodium endmember of the Plagioclase Solid solution series Oligoclase is a rock-forming Mineral belonging to the Plagioclase Feldspars In chemical composition and in its crystallographic and physical characters Andesine is a Feldspar Mineral, a part of the Plagioclase series Labradorite ((CaNa(AlSi4O8 a Feldspar Mineral, is an intermediate to calcic member of the Plagioclase series Bytownite is a calcium rich member of the Plagioclase Solid solution series of Feldspar Minerals It is usually defined as having "% Anorthite is a compositional variety of Plagioclase Feldspar. The immiscibility gaps in the plagioclase solid solution are complex compared to the gap in the alkali feldspars. A solid solution is a Solid - state Solution of one or more solutes in a Solvent. The play of colors visible in some feldspar of labradorite composition is due to very fine-grained exsolution lamellae.

The barium feldspars are monoclinic and comprise the following:

Uses

Feldspar output in 2005. Click the image for the details.
Feldspar output in 2005. Celsian is an uncommon Feldspar Mineral, barium aluminosilicate, BaAl2Si2O8 Hyalophane or jaloallofane is a crystalline mineral with chemical formula (KBa and a hardness of 6 – 6½ Click the image for the details.

In 2005, Italy was the top producer of feldspar with almost one-fifth world share followed by Turkey, China and Thailand, reports the International Monetary Fund. The International Monetary Fund ( IMF) is an International organization that oversees the Global financial system by following the Macroeconomic

References

  1. ^ a b c d e f Feldspar. What is Feldspar? Industrial Minerals Association. Retrieved on July 18, 2007. Events 390 BC - Roman - Gaulish Wars Battle of the Allia - a Roman army is defeated by raiding Gauls, Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century.
  2. ^ "Metamorphic Rocks. " Metamorphic Rocks Information. Retrieved on July 18, 2007. Events 390 BC - Roman - Gaulish Wars Battle of the Allia - a Roman army is defeated by raiding Gauls, Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century.
  3. ^ "Gem, Rock, and Mineral Postage Stamps Featuring Anorthosite. " Anorthosite Retrieved on February 8, 2008. Events 421 - Constantius III becomes co- Emperor of the Western Roman Empire. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common
  4. ^ "Weathering and Sedimentary Rocks. " Geology. Retrieved on July 18, 2007. Events 390 BC - Roman - Gaulish Wars Battle of the Allia - a Roman army is defeated by raiding Gauls, Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century.
  5. ^ Harper, Douglas. "Feldspar. " Feldspar Online Etymology Dictionary. Retrieved on February 8, 2008. Events 421 - Constantius III becomes co- Emperor of the Western Roman Empire. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common
  6. ^ a b "The Mineral Orthoclase. " Feldspar Amethyst Galleries, Inc. Retrieved on February 8, 2008. Events 421 - Constantius III becomes co- Emperor of the Western Roman Empire. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common
  7. ^ a b "Sanidine Feldspar. " Feldspar Amethyst Galleries, Inc. Retrieved on February 8, 2008. Events 421 - Constantius III becomes co- Emperor of the Western Roman Empire. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common
  8. ^ "Microcline Feldspar. " Feldspar Amethyst Galleries, Inc. Retrieved on February 8, 2008. Events 421 - Constantius III becomes co- Emperor of the Western Roman Empire. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common
  9. ^ Ralph, Jolyon & Ida. "Perthite. " Perthite Profile on mindat.org Retrieved on February 8, 2008. Events 421 - Constantius III becomes co- Emperor of the Western Roman Empire. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common

See also

This is a List of Minerals for which there are Wikipedia articles

Dictionary

feldspar

-noun

  1. (mineralogy) Any of a large group of rock-forming minerals that, together, make up about 60% of the earth's outer crust. The feldspars are all aluminum silicates of the alkali metals sodium, potassium, calcium and barium. Feldspars are the principal constituents of igneous and plutonic rocks.
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