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Brown Spar
Brown spar or ''brown-spar'' ()''Krivovichev V. G.'' Mineralogical glossary. Scientific editor :uk:Булах Андрій Глібович, A. G. Bulakh. — St.Petersburg: St.Petersburg Univ. Publ. House. 2009. — 556 p. — ISBN 978-5-288-04863-0 is a trivial name, trivial, partly obsolete name for at least ''four'' carbonate minerals that are relatively similar in composition: ankerite, Dolomite (mineral), dolomite (with varieties), magnesite (with varieties) and siderite,Bulletin of the United States National Museum. No.30. Published under the Directions of the Smithsonian Institution. — Washington: Government Printing Office, 1885. which have a characteristic dirty-brown hue due to the content of iron compounds, as well as an admixture of manganese oxide. As a consequence, many varieties of Dolomite (mineral), dolomite, colored brown or grey-brown by impurities, are also known as ''brown spar''. The name brown spar is both capacious and vividly descriptive, referring exclu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siderite
Siderite is a mineral composed of iron(II) carbonate (FeCO3). Its name comes from the Ancient Greek word (), meaning "iron". A valuable iron ore, it consists of 48% iron and lacks sulfur and phosphorus. Zinc, magnesium, and manganese commonly substitute for the iron, resulting in the siderite-smithsonite, siderite-magnesite, and siderite-rhodochrosite solid solution series. Siderite has Mohs hardness of 3.75 to 4.25, a specific gravity of 3.96, a white streak and a vitreous or pearly luster. Siderite is antiferromagnetic below its Néel temperature of that can assist in its identification. It crystallizes in the trigonal crystal system; crystals are rhombohedral in shape, typically with curved and striated faces. It also occurs in masses. Color ranges from yellow to dark brown or black, the latter being due to the presence of manganese. Siderite is commonly found in hydrothermal veins, and is associated with barite, fluorite, galena, and others. It is also a common ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrothermal Mineral Deposit
Hydrothermal mineral deposits are accumulations of valuable minerals which formed from Hydrothermal circulation, hot waters circulating in Earth's Crust (geology), crust through fractures. They eventually produce metallic-rich fluids concentrated in a selected volume of rock, which become Supersaturation, supersaturated and then Precipitation (chemistry), precipitate ore minerals. In some occurrences, minerals can be extracted for a profit by mining. Discovery of mineral deposits consumes considerable time and resources and only about one in every one thousand prospects explored by companies are eventually developed into a mine. A mineral deposit is any geologically significant concentration of an economically useful rock or mineral present in a specified area. The presence of a known but unexploited mineral deposit implies a lack of evidence for profitable extraction. Hydrothermal mineral deposits are divided into six main subcategories: Porphyry copper deposit, porphyry, skarn, vol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhombic Spar
Rhombic may refer to: *Rhombus, a quadrilateral whose four sides all have the same length (often called a diamond) *Rhombic antenna, a broadband directional antenna most commonly used on shortwave frequencies * polyhedra formed from rhombuses, such as the rhombic dodecahedron or the rhombic triacontahedron or the rhombic dodecahedral honeycomb or the rhombic icosahedron or the rhombic hexecontahedron or the rhombic enneacontahedron or the trapezo-rhombic dodecahedron * other things that exhibit the shape of a rhombus, such as rhombic tiling, Rhombic Chess, rhombic drive The rhombic drive is a specific method of transferring mechanical energy, or work, used when a single cylinder is used for two separately oscillating pistons. History It was originally developed around 1900 for the twin-cylinder Lanchester car e ..., Rhombic Skaapsteker, rhombic egg eater, rhombic night adder, forest rhombic night adder {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhomb Spar
In plane Euclidean geometry, a rhombus (: rhombi or rhombuses) is a quadrilateral whose four sides all have the same length. Another name is equilateral quadrilateral, since equilateral means that all of its sides are equal in length. The rhombus is often called a "diamond", after the diamonds suit in playing card A playing card is a piece of specially prepared card stock, heavy paper, thin cardboard, plastic-coated paper, cotton-paper blend, or thin plastic that is marked with distinguishing motifs. Often the front (face) and back of each card has a f ...s which resembles the projection of an Octahedron#Orthogonal projections, octahedral diamond, or a lozenge (shape), lozenge, though the former sometimes refers specifically to a rhombus with a 60° angle (which some authors call a calisson after calisson, the French sweet—also see Polyiamond), and the latter sometimes refers specifically to a rhombus with a 45° angle. Every rhombus is simple polygon, simple (non-self ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
