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Hendricksite
Hendricksite is a member of the trioctahedral micas group. The mineral was named by Clifford Frondel and Jun Ito in honor of Sterling Brown Hendricks, who studied micas. It was approved in 1966 by the IMA. Physical properties Hendricksite can either form short prismatic crystals, or foliated ones that are platy and seem two dimensional. It occurs in clusters, and these aggregates have interlocking crystals. These crystals are more commonly anhedral - a crystal with no faces, but rarely they can be euhedral - crystals with well defined surfaces. The anhedral crystals can grow up to 30 cm, and are commonly deformed, while the euhedral crystals can reach 14 cms in size of mechanical deformation. It has pleochroic attributes, which is an optical phenomenon that makes minerals to be seen a different color depending on the axis it is inspected on. On the X axis, it can be seen in a pale brown color, while on the Y and Z axis it is seen in a light chestnut brown color. It doesn't sho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoclinic
In crystallography, the monoclinic crystal system is one of the seven crystal systems. A crystal system is described by three vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in the orthorhombic system. They form a parallelogram prism. Hence two pairs of vectors are perpendicular (meet at right angles), while the third pair makes an angle other than 90°. Bravais lattices Two monoclinic Bravais lattices exist: the primitive monoclinic and the base-centered monoclinic. For the base-centered monoclinic lattice, the primitive cell has the shape of an oblique rhombic prism;See , row mC, column Primitive, where the cell parameters are given as a1 = a2, α = β it can be constructed because the two-dimensional centered rectangular base layer can also be described with primitive rhombic axes. Note that the length a of the primitive cell below equals \frac \sqrt of the conventional cell above. Crystal classes The table below org ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vesuvianite
Vesuvianite, also known as idocrase, is a green, brown, yellow, or blue silicate mineral. Vesuvianite occurs as tetragonal crystals in skarn deposits and limestones that have been subjected to contact metamorphism. It was first discovered within included blocks or adjacent to lavas on Mount Vesuvius, hence its name. Attractive-looking crystals are sometimes cut as gemstones. Localities which have yielded fine crystallized specimens include Mount Vesuvius and the Ala Valley near Turin, Piedmont. The specific gravity is 3.4 and the Mohs hardness The Mohs scale of mineral hardness () is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. The scale was introduced in 1812 by th ... is . The name "vesuvianite" was given by Abraham Gottlob Werner in 1795, because fine crystals of the mineral are found at Vesuvius; these are brown in color and occur in the ejected limeston ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mica Group
Micas ( ) are a group of silicate minerals whose outstanding physical characteristic is that individual mica crystals can easily be split into extremely thin elastic plates. This characteristic is described as perfect basal cleavage. Mica is common in igneous and metamorphic rock and is occasionally found as small flakes in sedimentary rock. It is particularly prominent in many granites, pegmatites, and schists, and "books" (large individual crystals) of mica several feet across have been found in some pegmatites. Micas are used in products such as drywalls, paints, fillers, especially in parts for automobiles, roofing and shingles, as well as in electronics. The mineral is used in cosmetics and food to add "shimmer" or "frost." Properties and structure The mica group is composed of 37 phyllosilicate minerals. All crystallize in the monoclinic system, with a tendency towards pseudohexagonal crystals, and are similar in structure but vary in chemical composition. Micas are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zinc Minerals
Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic table. In some respects, zinc is chemically similar to magnesium: both elements exhibit only one normal oxidation state (+2), and the Zn2+ and Mg2+ ions are of similar size.The elements are from different metal groups. See periodic table. Zinc is the 24th most abundant element in Earth's crust and has five stable isotopes. The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States. Zinc is refined by froth flotation of the ore, roasting, and final extraction using electricity ( electrowinning). Zinc is an essential trace element for humans, animals, plants and for microorganisms and is necessary for prenatal and postnatal development. It is the seco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hancockite
Epidote is a calcium aluminium iron sorosilicate mineral. Description Well developed crystals of epidote, Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH), crystallizing in the monoclinic system, are of frequent occurrence: they are commonly prismatic in habit, the direction of elongation being perpendicular to the single plane of symmetry. The faces are often deeply striated and crystals are often twinned. Many of the characters of the mineral vary with the amount of iron present for instance, the color, the optical constants, and the specific gravity. The color is green, grey, brown or nearly black, but usually a characteristic shade of yellowish-green or pistachio-green. It displays strong pleochroism, the pleochroic colors being usually green, yellow and brown. Clinozoisite is green, white or pale rose-red group species containing very little iron, thus having the same chemical composition as the orthorhombic mineral zoisite. The name, due to Haüy, is derived from the Greek word "epido ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Willemite
Willemite is a zinc silicate mineral () and a minor ore of zinc. It is highly fluorescent (green) under shortwave ultraviolet light. It occurs in a variety of colors in daylight, in fibrous masses and apple-green gemmy masses. Troostite is a variant in which part of the zinc is partly replaced by manganese, it occurs in solid brown masses. It was discovered in 1829 in the Belgian Vieille-Montagne mine. Armand Lévy was shown samples by a student at the university where he was teaching. Lévy named it after William I of the Netherlands (it is occasionally spelled villemite). The troostite variety is named after Dutch-American mineralogist Gerard Troost. Occurrence Willemite is usually formed as an alteration of previously existing sphalerite ore bodies, and is usually associated with limestone. It is also found in marble and may be the result of a metamorphism of earlier hemimorphite or smithsonite. Crystals have the form of hexagonal prisms terminated by rhombohedral planes: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhodonite
Rhodonite is a manganese silicate minerals, inosilicate, (Mn, Fe, Mg, Ca)SiO3 and member of the pyroxenoid group of minerals, crystallizing in the triclinic system. It commonly occurs as cleavable to compact masses with a rose-red color (the name comes from the Greek ῥόδος ''rhodos'', rosy), often tending to brown because of surface redox, oxidation. Rhodonite crystals often have a thick tabular crystal habit, habit, but are rare. It has a perfect, prismatic Cleavage (crystal), cleavage, almost at right angles. The Mohs scale of mineral hardness, hardness is 5.5–6.5, and the specific gravity is 3.4–3.7; lustre (mineralogy), luster is vitreous, being less frequently pearly on cleavage surfaces. The manganese is often partly replaced by iron, magnesium, calcium, and sometimes zinc, which may sometimes be present in considerable amounts; a greyish-brown variety containing as much as 20% of calcium oxide is called ''bustamite''; ''fowlerite'' is a zinciferous variety containi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcite
Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on the Mohs scale of mineral hardness, based on Scratch hardness, scratch hardness comparison. Large calcite crystals are used in optical equipment, and limestone composed mostly of calcite has numerous uses. Other polymorphs of calcium carbonate are the minerals aragonite and vaterite. Aragonite will change to calcite over timescales of days or less at temperatures exceeding 300 °C, and vaterite is even less stable. Etymology Calcite is derived from the German ''Calcit'', a term from the 19th century that came from the Latin word for Lime (material), lime, ''calx'' (genitive calcis) with the suffix "-ite" used to name minerals. It is thus etymologically related to chalk. When applied by archaeology, archaeologists and stone trade pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axinite
Axinite is a brown to violet-brown, or reddish-brown bladed group of minerals composed of calcium aluminium boro-silicate, . Axinite is pyroelectric and piezoelectric. The axinite group includes: *Axinite-(Fe) or ferroaxinite, Ca2Fe2+Al2BOSi4O15(OH) iron rich, clove-brown, brown, plum-blue, pearl-gray *Axinite-(Mg) or magnesioaxinite, Ca2MgAl2BOSi4O15(OH) magnesium rich, pale blue to pale violet; light brown to light pink *Axinite-(Mn) or manganaxinite, Ca2Mn2+Al2BOSi4O15(OH) manganese rich, honey-yellow, clove-brown, brown to blue *Tinzenite, (CaFe2+Mn2+)3Al2BOSi4O15(OH) iron – manganese intermediate, yellow, brownish yellow-green Axinite is sometimes used as a gemstone.Tables of Gemstone Identification By Roger Dedeyne, Ivo Quintens p.147 Gallery File:Axinite-64246.jpg, Clove-brown axinite crystals to 2.3 cm set atop matrix from the West Bor Pit at Dalnegorsk, Russia File:Axinite-60191.jpg, Chloritized bladed crystals of Axinite forming on Adularia from the Swiss Alps F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feldspars
Feldspars are a group of rock-forming aluminium tectosilicate minerals, also containing other cations such as sodium, calcium, potassium, or barium. The most common members of the feldspar group are the ''plagioclase'' (sodium-calcium) feldspars and the ''alkali'' (potassium-sodium) feldspars. Feldspars make up about 60% of the Earth's crust, and 41% of the Earth's continental crust by weight. Feldspars crystalize from magma as both intrusive and extrusive igneous rocks and are also present in many types of metamorphic rock. Rock formed almost entirely of calcic plagioclase feldspar is known as anorthosite. Feldspars are also found in many types of sedimentary rocks. Compositions The feldspar group of minerals consists of tectosilicates, silicate minerals in which silicon ions are linked by shared oxygen ions to form a three-dimensional network. Compositions of major elements in common feldspars can be expressed in terms of three endmembers: * potassium feldspar (K-spar) en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bustamite
Bustamite is a calcium manganese inosilicate (chain silicate) and a member of the wollastonite group. Magnesium, zinc and iron are common impurities substituting for manganese. Bustamite is the high-temperature polymorph of CaMnSi2O6 and johannsenite is the low temperature polymorph. The inversion takes place at , but may be very slow.Deer, W A, Howie, R A and Zussman, J (1978) Rock-Forming Minerals, 2nd edition, Volume 2A, pages 574-585Bustamite could be confused with light-colored rhodonite or pyroxmangite, but both these minerals are biaxial (+) whereas bustamite is biaxial (-). Cell parameters There is considerable variety in the literature about the size and type of the unit cell, the formula to be used, and the value of Z, the number of formula units per unit cell. Bustamite is a triclinic mineral, which could be described by a primitive unit cell, but the larger A-centered cell is often preferred, in order to facilitate comparison with the similar mineral wollastonite.Pea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
