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Vugs
A vug, vugh, or vugg () is a small- to medium-sized cavity inside rock. It may be formed through a variety of processes. Most commonly, cracks and fissures opened by tectonic activity ( folding and faulting) are partially filled by quartz, calcite, and other secondary minerals. Open spaces within breccias formed by an ancient collapse are another important source of vugs. Vugs may also form when mineral crystals or fossils inside a rock matrix are later removed through erosion or dissolution processes, leaving behind irregular voids. The inner surfaces of such vugs are often coated with a crystal druse. Fine crystals are often found in vugs where the open space allows the free development of external crystal form. The term ''vug'' is not applied to veins and fissures that have become completely filled, but may be applied to any small cavities within such veins. Geodes are a vug-formed rock, although that term is usually reserved for more rounded crystal-lined cavities in sed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geode
A geode (; ) is a geology, geological secondary formation within sedimentary rock, sedimentary and volcanic rocks. Geodes are hollow, vaguely spherical rocks, in which masses of mineral matter (which may include crystals) are secluded. The crystals are formed by the filling of vesicular texture, vesicles in volcanic and subvolcanic rocks by minerals deposited from hydrothermal fluids; or by the solvation, dissolution of syngenetic concretions and partial filling by the same or other minerals precipitation (chemistry), precipitated from water, groundwater, or hydrothermal fluids. Formation Geodes can form in any cavity, but the term is usually reserved for more or less rounded formations in igneous and sedimentary rocks. They can form in gas bubbles in igneous rocks, such as vesicles in basaltic lava; or, as in the American Midwest, in rounded cavities in sedimentary formations. After rock around the cavity hardens, dissolved silicates and/or carbonates are deposited on the ins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyromorphite
Pyromorphite is a mineral species composed of lead chlorophosphate: Pb5( P O4)3 Cl, sometimes occurring in sufficient abundance to be mined as an ore of lead. Crystals are common, and have the form of a hexagonal prism terminated by the basal planes, sometimes combined with narrow faces of a hexagonal pyramid. Crystals with a barrel-like curvature are not uncommon. Globular and reniform masses are also found. Pyromorphite is part of the apatite group of minerals and bears a close resemblance physically and chemically with two other minerals: mimetite (Pb5( AsO4)3Cl) and vanadinite (Pb5( VO4)3Cl). The resemblance in external characters is so close that, as a rule, it is only possible to distinguish between them by chemical tests. They were formerly confused under the names green lead ore and brown lead ore (''German: Grünbleierz and Braunbleierz''). History The mineral was first distinguished chemically by M. H. Klaproth in 1784, and it was named pyromorphite by J. F. L. H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rosasite
Rosasite is a carbonate mineral with minor potential for use as a zinc and copper ore. Chemically, it is a copper zinc carbonate hydroxide with a copper to zinc ratio of 3:2, occurring in the secondary oxidation zone of copper-zinc deposits. It was originally discovered in 1908 in the Rosas mine in Sardinia, Italy, and is named after the location. Fibrous blue-green rosasite crystals are usually found in globular aggregates, often associated with red limonite and other colorful minerals. It is very similar to aurichalcite Aurichalcite is a carbonate mineral, usually found as a secondary mineral in copper and zinc deposits. Its chemical formula is . The zinc to copper ratio is about 5:4. Copper (Cu2+) gives aurichalcite its green-blue colors. Occurrence Aurichalci ..., but can be distinguished by its superior hardness. References Mineral galleries Copper(II) minerals Zinc minerals Carbonate minerals Monoclinic minerals Minerals in space group 14 Minerals described in 1908< ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heulandite
Heulandite is the name of a series of tectosilicate minerals of the zeolite group. Prior to 1997, heulandite was recognized as a mineral species, but a reclassification in 1997 by the International Mineralogical Association changed it to a series name, with the mineral species being named: * Heulandite-Ca * Heulandite-Na * Heulandite-K * Heulandite-Sr * Heulandite-Ba (described in 2002). Heulandite-Ca, the most common of these, is a hydrous calcium and aluminium silicate with the formula . Small amounts of sodium and potassium are usually present replacing part of the calcium. Strontium replaces calcium in the heulandite-Sr variety. The appropriate species name depends on the dominant element. The species are visually indistinguishable, and the series name heulandite is still used whenever testing has not been performed. Crystallography and properties Crystals are monoclinic. They may have a characteristic coffin-shaped habit, but may also form simple rhombic prisms. Freque ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azurite
Azurite or '' Azure spar''''Krivovichev V. G.'' Mineralogical glossary. Scientific editor A. G. Bulakh. — St.Petersburg: St.Petersburg Univ. Publ. House. 2009. — 556 p. — ISBN 978-5-288-04863-0. ''(in Russian)'' is a soft, deep-blue copper mineral produced by weathering of copper ore deposits. During the early 19th century, it was also known as chessylite, after the type locality at Chessy-les-Mines near Lyon, France. The mineral, a basic carbonate with the chemical formula Cu3(CO3)2(OH)2, has been known since ancient times, and was mentioned in Pliny the Elder's '' Natural History'' under the Greek name (κυανός: "deep blue," root of English cyan) and the Latin name '' caeruleum''. Copper (Cu2+) gives it its blue color. Mineralogy Azurite has the formula Cu3(CO3)2(OH)2, with the copper(II) cations linked to two different anions, carbonate and hydroxide. It is one of two relatively common basic copper(II) carbonate minerals, the other being bright green malach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conichalcite
Conichalcite, Ca Cu( As O4)(O H), is a relatively common arsenate mineral related to duftite ( PbCu(AsO4)(OH)). It is green, often botryoidal, and occurs in the oxidation zone of some metal deposits. It occurs with limonite, malachite, beudantite, adamite, cuproadamite, olivenite and smithsonite. Formation Conichalcite forms in the oxidation zones of copper orebodies. Here groundwater enriched with oxygen reacts with copper sulfide and copper oxide to produce an array of minerals such as malachite, azurite and linarite. Conichalcite is often found encrusted on to limonitic rocks that have yellow to red colors. Conichalcite will also form a solid solution series with the mineral calciovolborthite. When these two minerals form a solid solution series, the two interchanging elements are arsenic and vanadium. Conichalcite is the arsenic rich end member of the series and calciovolborthite is the vanadium rich end member. Notable occurrences of conichalcite include Jua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limonite
Limonite () is an iron ore consisting of a mixture of hydrated iron(III) oxide-hydroxides in varying composition. The generic formula is frequently written as , although this is not entirely accurate as the ratio of oxide to hydroxide can vary quite widely. Limonite is one of the three principal iron ores, the others being hematite and magnetite, and has been mining, mined for the production of iron since at least 400 BC. Names Limonite is named for the Ancient Greek word ( ), meaning "wet meadow", or ( ), meaning "marshy lake", as an allusion to its occurrence as in meadows and marshes. In its brown form, it is sometimes called brown hematite or brown iron ore. Characteristics Limonite is relatively density, dense with a specific gravity varying from 2.7 to 4.3.Northrop, Stuart A. (1959) "Limonite" ''Minerals of New Mexico'' (revised edition) University of New Mexico Press, Albuquerque, New Mexico, pp. 329–333, It is usually medium to dark yellowish brown in color. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cornish Language
Cornish (Standard Written Form: or , ) is a Southwestern Brittonic language, Southwestern Brittonic language of the Celtic language family. Along with Welsh language, Welsh and Breton language, Breton, Cornish descends from Common Brittonic, a language once spoken widely across Great Britain. For much of the Middle Ages, medieval period Cornish was the main language of Cornwall, until it was gradually pushed westwards by the spread of English language, English. Cornish remained a vernacular, common community language in parts of Cornwall until the mid-18th century, and there is some evidence for traditional speakers persisting into the 19th century. Cornish became extinct language, extinct as a living community language in Cornwall by the last speaker of the Cornish language, end of the 18th century, although knowledge of Cornish, including speaking ability to a certain extent, persisted within some families and individuals. Cornish language revival, A revival started in the e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Polwhele
Richard Polwhele (6 January 1760 – 12 March 1838) was a Cornish clergyman, poet and historian of Cornwall and Devon. Biography Richard Polwhele's ancestors long held the manor of Treworgan, 4 3/4 miles south-east of Truro in Cornwall, which family bore as arms: ''Sable, a saltire engrailed ermine''. He was born at Truro, Cornwall, and met literary luminaries Catharine Macaulay and Hannah More at an early age. He was educated at Truro Grammar School, where he precociously published ''The Fate of Llewellyn''. He went on to Christ Church, Oxford, continuing to write poetry, but left without taking a degree. In 1782 he was ordained a curate, married Loveday Warren, and moved to a curacy at Kenton, Devon. On his wife's death in 1793, Polwhele was left with three children. Later that year he married Mary Tyrrell, briefly taking up a curacy at Exmouth before being appointed to the small living of Manaccan in Cornwall in 1794. From 1806, when he took up a curacy at Kenwyn, Tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mining
Mining is the Resource extraction, extraction of valuable geological materials and minerals from the surface of the Earth. Mining is required to obtain most materials that cannot be grown through agriculture, agricultural processes, or feasibly created Chemical synthesis, artificially in a laboratory or factory. Ores recovered by mining include Metal#Extraction, metals, coal, oil shale, gemstones, limestone, chalk mining, chalk, dimension stone, rock salt, potash, gravel, and clay. The ore must be a rock or mineral that contains valuable constituent, can be extracted or mined and sold for profit. Mining in a wider sense includes extraction of any non-renewable resource such as petroleum, natural gas, or even fossil water, water. Modern mining processes involve prospecting for ore bodies, analysis of the profit potential of a proposed mine, extraction of the desired materials, and final mine reclamation, reclamation or restoration of the land after the mine is closed. Mining ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
