"(including electrical insulators, sanitaryware, pottery, tableware, and tile) and other uses, such as fillers, accounted for the remainder. In earth sciences and archaeology, feldspars are used for K-Ar dating, argon-argon dating, and luminescence dating. In October 2012, the Mars Curiosity rover analyzed a rock that turned out to have a high feldspar content. Feldspar Feldspars (KAlSiO – NaAlSiO – CaAlSiO) are a group of rock-forming tectosilicate minerals that make up about 41% of the Earth's continental crust by weight. Feldspars crystallize from magma as veins in both intrusive and extrusive igneous rocks and are also present in many types of"
"most abundant element on Earth, but only the fourth most abundant element in the Earth's crust, after oxygen, silicon, and aluminium. Most of the iron in the crust is found combined with oxygen as iron oxide minerals such as hematite (FeO), magnetite (FeO), and siderite (FeCO). Many igneous rocks also contain the sulfide minerals pyrrhotite and pentlandite. Ferropericlase (Mg,Fe)O, a solid solution of periclase (MgO) and wüstite (FeO), makes up about 20% of the volume of the lower mantle of the Earth, which makes it the second most abundant mineral phase in that region after silicate perovskite (Mg,Fe)SiO; it also"
"Orthosilicate In chemistry, orthosilicate is the anion , or any of its salts and esters. It is one of the silicate anions. It is occasionally called the silicon tetroxide anion or group. Orthosilicate salts, like sodium orthosilicate, are stable, and occur widely in nature as silicate minerals, being the defining feature of the nesosilicates. Olivine, a magnesium or iron(II) orthosilicate, is the most abundant mineral in the Earth's mantle. The orthosilicate anion is a strong base, the conjugate base of the extremely weak orthosilicic acid (p""K"" = 13.2 at 25 °C). This equilibrium is difficult to study since the acid"
"Earth's crust, quartz (SiO) is the most abundant mineral species. It is characterized by its high chemical and physical resistivity. Quartz has several polymorphs, including tridymite and cristobalite at high temperatures, high-pressure coesite, and ultra-high pressure stishovite. The latter mineral can only be formed on Earth by meteorite impacts, and its structure has been composed so much that it had changed from a silicate structure to that of rutile (TiO). The silica polymorph that is most stable at the Earth's surface is α-quartz. Its counterpart, β-quartz, is present only at high temperatures and pressures (changes to α-quartz below 573 °C"
"sheet silicates, form parallel sheets of silicate tetrahedra with SiO or a 2:5 ratio. The Nickel–Strunz classification is 09.E. All phyllosilicate minerals are hydrated, with either water or hydroxyl groups attached. Examples include: Tectosilicates, or ""framework silicates,"" have a three-dimensional framework of silicate tetrahedra with SiO or a 1:2 ratio. This group comprises nearly 75% of the crust of the Earth. Tectosilicates, with the exception of the quartz group, are aluminosilicates. The Nickel–Strunz classifications are 09.F and 09.G, 04.DA (Quartz/ silica family). Examples include: Silicate minerals Silicate minerals are rock-forming minerals with predominantly silicate anions. They are the largest and"
"minerals, such as augite, hornblende, enstatite or biotite, occur rather than olivine. Unless potash is high and silica relatively low, leucite will not be present, for leucite does not occur with free quartz. Nepheline, likewise, is usually found in rocks with much soda and comparatively little silica. With high alkalis, soda-bearing pyroxenes and amphiboles may be present. The lower the percentage of silica and alkali's, the greater is the prevalence of plagioclase feldspar as contracted with soda or potash feldspar. Earth's crust is composed of 90% silicate minerals and their abundance in the Earth is as follows: plagioclase feldspar (39%),"
"in trace amounts in earth's atmosphere. Silicate minerals are the most common type of mineral on earth. Silicon makes up 14.3 parts per million of the human body on average. Only the largest stars produce silicon via stellar fusion. Germanium makes up 2 parts per million of the earth's crust, making it the 52nd most abundant element there. On average, germanium makes up 1 part per million of soil. Germanium makes up 0.5 parts per trillion of seawater. Organogermanium compounds are also found in seawater. Germanium occurs in the human body at concentrations of 71.4 parts per billion. Germanium has"
"Family, Tribe, Genus, and Species. The abundance and diversity of minerals is controlled directly by their chemistry, in turn dependent on elemental abundances in the Earth. The majority of minerals observed are derived from the Earth's crust. Eight elements account for most of the key components of minerals, due to their abundance in the crust. These eight elements, summing to over 98% of the crust by weight, are, in order of decreasing abundance: oxygen, silicon, aluminium, iron, magnesium, calcium, sodium and potassium. Oxygen and silicon are by far the two most important – oxygen composes 47% of the crust by"
"thousands of known forms. In contrast, a rock sample is a random aggregate of minerals and/or mineraloids, and has no specific chemical composition. The vast majority of the rocks of the Earth's crust consist of quartz (crystalline SiO), feldspar, mica, chlorite, kaolin, calcite, epidote, olivine, augite, hornblende, magnetite, hematite, limonite and a few other minerals. Some minerals, like quartz, mica or feldspar are common, while others have been found in only a few locations worldwide. The largest group of minerals by far is the silicates (most rocks are ≥95% silicates), which are composed largely of silicon and oxygen, with the"
"elements in Earth's crust, having an average mass fraction of 0.001 ppm in crustal rock; platinum is 10 times more abundant, gold is 40 times more abundant, and silver and mercury are 80 times more abundant. Tellurium is about as abundant as iridium. In contrast to its low abundance in crustal rock, iridium is relatively common in meteorites, with concentrations of 0.5 ppm or more. The overall concentration of iridium on Earth is thought to be much higher than what is observed in crustal rocks, but because of the density and siderophilic (""iron-loving"") character of iridium, it descended below the"
"in some of the most distant stars and in the atmosphere of Jupiter. Germanium's abundance in the Earth's crust is approximately 1.6 ppm. Only a few minerals like argyrodite, briartite, germanite, and renierite contain appreciable amounts of germanium. Only few of them (especially germanite) are, very rarely, found in mineable amounts. Some zinc-copper-lead ore bodies contain enough germanium to justify extraction from the final ore concentrate. An unusual natural enrichment process causes a high content of germanium in some coal seams, discovered by Victor Moritz Goldschmidt during a broad survey for germanium deposits. The highest concentration ever found was in"
"Natrolite Natrolite is a tectosilicate mineral species belonging to the zeolite group. It is a hydrated sodium and aluminium silicate with the formula . The type locality is Hohentwiel, Hegau, Germany. It was named natrolite by Martin Heinrich Klaproth in 1803. The name is derived from νατρών natron, the Greek word for soda, in reference to the sodium content and λίθος lithos, meaning stone. Needle stone or needle-zeolite are other informal names, alluding to the common acicular habit of the crystals, which are often very slender and are aggregated in divergent tufts. The crystals are frequently epitaxial overgrowths of natrolite,"
"(to illustrate, tellurium is only about as abundant as platinum). The most metallic chalcophile elements (of the copper, zinc and boron groups) may mix to some degree with iron in the Earth's core. They are not likely to be depleted on Earth as a whole relative to their solar abundances since they do not form volatile hydrides. Zinc and gallium are somewhat ""lithophile"" in nature because they often occur in silicate or related minerals and form quite strong bonds with oxygen. Gallium, notably, is sourced mainly from bauxite, an aluminum hydroxide ore in which gallium ion substitutes for chemically similar"
"occurring, often form rounded nodules of troilite or graphite, surrounded by schreibersite and cohenite. Schreibersite and troilite also occur as plate shaped inclusions, which show up on cut surfaces as cm-long and mm-thick lamellae. The troilite plates are called ""Reichenbach lamellae"". The chemical composition is dominated by the elements Fe, Ni and Co, which make up more than 95%. Ni is always present; the concentration is nearly always higher than 5% and may be as high as about 25%. A significant percentage of nickel can be used in the field to distinguish meteoritic irons from man-made iron products, which usually"
"alkali feldspar (12%), quartz (12%), pyroxene (11%), amphiboles (5%), micas (5%), clay minerals (5%); the remaining silicate minerals make up another 3% of Earth's crust. Only 8% of the Earth is composed of non-silicate minerals such as carbonates, oxides, and sulfides. The other determining factor, namely the physical conditions attending consolidation, plays on the whole a smaller part, yet is by no means negligible. Certain minerals are practically confined to deep-seated intrusive rocks, e.g., microcline, muscovite, diallage. Leucite is very rare in plutonic masses; many minerals have special peculiarities in microscopic character according to whether they crystallized in depth or"
"from German ""Feldspat"", which derives from German ""Feld"", meaning ""field"". In order for a rock to be classified as felsic, it generally needs to contain more than 75% felsic minerals; namely quartz, orthoclase and plagioclase. Rocks with greater than 90% felsic minerals can also be called leucocratic, meaning 'light-coloured'. Felsite is a petrologic field term used to refer to very fine-grained or aphanitic, light-colored volcanic rocks which might be later reclassified after a more detailed microscopic or chemical analysis. In some cases, felsic volcanic rocks may contain phenocrysts of mafic minerals, usually hornblende, pyroxene or a feldspar mineral, and may"
"stacking groups of three layers (""abcabcabc""). Analogues to linked silica tetrahedra include SO (sulfate), PO (phosphate), AsO (arsenate), and VO (vanadate). The non-silicates have great economic importance, as they concentrate elements more than the silicate minerals do. The largest grouping of minerals by far are the silicates; most rocks are composed of greater than 95% silicate minerals, and over 90% of the Earth's crust is composed of these minerals. The two main constituents of silicates are silicon and oxygen, which are the two most abundant elements in the Earth's crust. Other common elements in silicate minerals correspond to other common"
"tenacity, cleavage, fracture, parting, specific gravity, magnetism, taste or smell, radioactivity, and reaction to acid. Minerals are classified by key chemical constituents; the two dominant systems are the Dana classification and the Strunz classification. Silicon and oxygen constitute approximately 75% of the Earth's crust, which translates directly into the predominance of silicate minerals. The silicate minerals compose over 90% of the Earth's crust. The silicate class of minerals is subdivided into six subclasses by the degree of polymerization in the chemical structure. All silicate minerals have a base unit of a [SiO] silica tetrahedron—that is, a silicon cation coordinated by"
"since decayed and no longer contribute. In the Earth's crust, thorium is much more abundant: with an abundance of 8.1 parts per million (ppm), it is one of the most abundant of the heavy elements, almost as abundant as lead (13 ppm) and more abundant than tin (2.1 ppm). This is because thorium is likely to form oxide minerals that do not sink into the core; it is classified as a lithophile. Common thorium compounds are also poorly soluble in water. Thus, even though the Earth contains the same abundances of the elements as the Solar System as a whole,"
"Sial In geology, the term 'sial' refers to the composition of the upper layer of the Earth's crust, namely rocks rich in silicates and aluminium minerals. It is sometimes equated with the continental crust because it is absent in the wide oceanic basins, but ""sial"" is a geochemical term rather than a plate tectonic term. As these elements are less dense than the majority of the earth's elements, they tend to be concentrated in the upper layer of the crust. Geologists often refer to the rocks in this layer as felsic, because they contain high levels of feldspar, an aluminium"
"up about 20% of the volume of the lower mantle of the Earth, which makes it the second most abundant mineral phase in that region after silicate perovskite (Mg,Fe)SiO; it also is the major host for iron in the lower mantle. At the bottom of the transition zone of the mantle, the reaction γ-(Mg,Fe)[SiO] ↔ (Mg,Fe)[SiO] + (Mg,Fe)O transforms γ-olivine into a mixture of perovskite and ferropericlase and vice versa. In the literature, this mineral phase of the lower mantle is also often called magnesiowüstite. Periclase Periclase is a magnesium mineral that occurs naturally in contact metamorphic rocks and is"
"natrolite have been distinguished by special Nips. Fargite is a red natrolite from Glenfarg in Perthshire. Bergmannite, or Spreustein, is an impure variety which has resulted by the alteration of other minerals, chiefly sodalite, in the augite syenite of southern Norway. Natrolite Natrolite is a tectosilicate mineral species belonging to the zeolite group. It is a hydrated sodium and aluminium silicate with the formula . The type locality is Hohentwiel, Hegau, Germany. It was named natrolite by Martin Heinrich Klaproth in 1803. The name is derived from νατρών natron, the Greek word for soda, in reference to the sodium content"
"Flint field Flint fields () are large natural deposits of flint. They are found in numerous Jurassic and Cretaceous beds across the whole of Europe. Such deposits may be found in Aachen-Lousberg, Kleinkems, Schernfeld, Osterberg bei Pfünz, Baiersdorf, Abensberg-Arnhofen and Lengfeld as well as the German island of Rügen. The flint fields on Germany's biggest island, Rügen, between Mukran and Prora in the northern part of the heath of Schmale Heide are part of the Stone Fields in the Schmale Heath and Extension nature reserve. They were also called the ""Steinernes Meer"" (""stony sea"") and have an area of 40"
"Silicate minerals Silicate minerals are rock-forming minerals with predominantly silicate anions. They are the largest and most important class of rock-forming minerals and make up approximately 90 percent of the Earth's crust. In mineralogy, silica, or silicon dioxide SiO, which corresponds to ""x""=2 in the general formula, is usually considered a silicate mineral—even though its silicate ""anion"" has no negative charge and it has no cations. Silica is found in nature as the mineral quartz, and its polymorphs. On Earth, a wide variety of silicate minerals occur in an even wider range of combinations as a result of the processes"
"Fuchsite Fuchsite, also known as chrome mica, is a chromium (Cr) rich variety of the mineral muscovite, belonging to the mica group of phyllosilicate minerals, with the following formula: K(Al,Cr)(AlSiO)(OH). Trivalent chromium replaces one of the aluminium (Al) atoms in the general muscovite formula producing the apple green hue distinctive of fuchsite. It is often found in minute micaceous aggregates (with individual plates barely visible), as a major component of chromium rich phyllitic or schistose metamorphic rocks of the greenschist facies. Verdite is an impure often multicolored variety of fuchsite used for ornamental carvings. Fuchsite is named after the German"
"laumontite or colorless, pale green or white fluorapophyllite. It is also found in the region as massive radiating material with powellite, and in cavities in basalt as colorless, flattened crystals in radiating sprays on blocky green apophyllite covered by tiny, thin, colorless apophyllite plates. Scolecite has been reported from many other localities, including Antarctica, Australia, Austria, Brazil, Bulgaria, Canada, Chile, Czechoslovakia, Ethiopia, Faroe Islands, France, Germany, Greenland, Hungary, Iceland, Italy, Japan, Mexico, Mozambique, Nicaragua, Peru, Poland, South Africa, Sweden, Switzerland, Taiwan, United Kingdom, United States and Yugoslavia. Scolecite Scolecite is a tectosilicate mineral belonging to the zeolite group; it is"
"with slightly less metal than the chemical formula would show. For example, the mineral FeO (wüstite) is written as , where ""x"" is usually around 0.05. Oxygen is present in the atmosphere in trace quantities in the form of carbon dioxide (). The Earth's crustal rock is composed in large part of oxides of silicon (silica , as found in granite and quartz), aluminium (aluminium oxide , in bauxite and corundum), iron (iron(III) oxide , in hematite and rust), and calcium carbonate (in limestone). The rest of the Earth's crust is also made of oxygen compounds, in particular various complex"
"a phosphate of numerous group 3 + lanthanide + actinide metals and mined especially for the thorium content and specific rare earths especially lanthanum, yttrium and cerium. Cerium and lanthanum as well as other members of the rare earth series are often produced as a metal called mischmetal containing a variable mixture of the these elements with cerium and lanthanum predominating; it has direct uses such as lighter flints and other spark sources which do not require extensive purification of one of these metals. There are also rare earth-bearing minerals based on group 2 elements such as yttrocalcite, yttrocerite, yttrofluorite"
"rhodium, palladium, osmium, iridium, and platinum), germanium, and tin—can be counted as siderophiles but only in terms of their primary occurrence in the Earth (core, mantle and crust), rather the crust. These metals otherwise occur in the crust, in small quantities, chiefly as chalcophiles (less so in their native form). The rotating fluid outer core of the Earth's interior, which is composed mostly of iron, is thought to be the source of Earth's protective magnetic field. The core lies above Earth's solid inner core and below its mantle. If it could be rearranged into a column having a 5m footprint"
"several zinc ores, but only in minute quantities; likewise some copper and lead ores contain traces. As is the case for most other elements found in ores and minerals, the indium extraction process has become more efficient in recent years, ultimately leading to larger yields. Canada is the world's leader in indium reserves, but both the United States and China have comparable amounts. Thallium is neither rare nor common in the Earth's crust, but falls somewhere in the middle. Its abundance is estimated to be 0.00006% (0.6 ppm). Thallium is the 56th most common element in the earth's crust, more"
"Buntsandstein (Early Triassic) siliciclastic rocks, Muschelkalk (Middle Triassic) marine limestones, Keuper (Middle and Late Triassic) mixed evaporite-carbonate-siliciclastic deposits, Early Jurassic (Lias/Schwarzjura) marine black shales, Dogger/Braunjura (Middle Jurassic) marine, often iron-bearing, siliciclastic rocks, White Jurassic/Malm (Late Jurassic) marine limestones, Early Cretaceous (Wealden) continental siliciclastic rocks and Late Cretaceous marine limestones, sandstones and gaizes. Outcropping Zechstein rocks are limited to the edges of basement uplifts. Triassic rocks cover the largest area. In the South German Block, extensively outcropping Mesozoic rocks dip towards the south-east. Due to the alternating layering of weathering/erosion-prone shales and more resistant sandstones and limestones, a cuesta landscape has"
"the Earth's heterosphere, a part of the upper atmosphere, helium and other lighter gases are the most abundant elements. Most helium on Earth is a result of radioactive decay. Helium is found in large amounts in minerals of uranium and thorium, including cleveite, pitchblende, carnotite and monazite, because they emit alpha particles (helium nuclei, He) to which electrons immediately combine as soon as the particle is stopped by the rock. In this way an estimated 3000 metric tons of helium are generated per year throughout the lithosphere. In the Earth's crust, the concentration of helium is 8 parts per billion."
"earth's crust at a concentration of two to six parts per million (ppm), much of which is in soils, where it has a concentration of six ppm. Beryllium is one of the rarest elements in seawater, even rarer than elements such as scandium, with a concentration of 0.2 parts per trillion. However, in freshwater, beryllium is somewhat more common, with a concentration of 0.1 parts per billion. Magnesium and calcium are very common in the earth's crust, being respectively the fifth- eighth-most-abundant elements. None of the alkaline earth metals are found in their elemental state. Common magnesium--containing minerals are carnallite,"