|
Polymetallic Ore
Polymetallic ores or multimetal ores are complex ores containing a number of chemical elements, among which the most important are lead and zinc. In addition, polymetallic ores can contain copper, gold, silver, cadmium, sometimes bismuth, tin, indium and gallium. The main minerals that form polymetallic ores are galena, sphalerite, to a lesser extent pyrite, chalcopyrite, arsenopyrite, cassiterite. They are most commonly formed from sulfides but also include oxides. The three main families of sulfide polymetallic ores are identified as volcanogenic massive sulphide family, the sedimentary exhalative family, and the Mississippi Valley type family. The classification of lead-zinc deposits in particular has been varied and resulted in a number of different organizations schemes. The term "polymetallic ore" also includes nodules, principally Manganese nodules, that do not form as terrestrial deposits but as concretions on the ocean floor. Rocks containing polymetallic ores are oft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ores
Ore is natural Rock (geology), rock or sediment that contains one or more valuable minerals, typically including metals, concentrated above background levels, and that is economically viable to mine and process. The grade of ore refers to the concentration of the desired material it contains. The value of the metals or minerals a rock contains must be weighed against the cost of extraction to determine whether it is of sufficiently high grade to be worth mining and is therefore considered an ore. A complex ore is one containing more than one valuable mineral. Minerals of interest are generally Oxide mineral, oxides, Sulfide mineral, sulfides, Silicate minerals, silicates, or native metals such as Native copper, copper or gold. Ore bodies are formed by a variety of Geology, geological processes generally referred to as ore genesis and can be classified based on their deposit type. Ore is extracted from the earth through mining and treated or Refining (metallurgy), refined, ofte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbonate-hosted Lead-zinc Ore Deposits
Carbonate-hosted lead-zinc ore deposits are important and highly valuable concentrations of lead and zinc sulfide ores hosted within carbonate (limestone, marl, dolomite) formations and which share a common genetic origin. These ore bodies range from 0.5 million tonnes of contained ore, to 20 million tonnes or more, and have a grade of between 4% combined lead and zinc to over 14% combined lead and zinc. These ore bodies tend to be compact, fairly uniform plug-like or pipe-like replacements of their host carbonate sequences and as such can be extremely profitable mines. This classification of ore deposits is also known as Mississippi Valley Type or MVT ore deposits, after a number of such deposits along the Mississippi River in the United States, where such ores were first recognised; these include the famed Southeast Missouri Lead District of southeastern Missouri, and deposits in northeast Iowa, southwest Wisconsin, and northwest Illinois. Similarly Irish-type carbonate l ... [...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] |
Malachite
Malachite () is a copper Carbonate mineral, carbonate hydroxide mineral, with the chemical formula, formula Basic copper carbonate, Cu2CO3(OH)2. This opaque, green-banded mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagmite, stalagmitic masses, in fractures and deep, underground spaces, where the water table and hydrothermal fluids provide the means for chemical precipitation. Individual crystals are rare, but occur as slender to Acicular (crystal habit), acicular prisms. Pseudomorphs after more tabular or blocky azurite crystals also occur. Etymology and history The stone's name derives (via , , and Middle English ''melochites'') from Greek language, Greek Μολοχίτης λίθος ''molochites lithos'', "mallow-green stone", from μολόχη ''molochē'', variant of μαλάχη ''malāchē'', "mallow". The mineral was given this name due to its resemblance to the leaves of the Malva, mallow plant. Copper (Cu2+) g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calamine
Calamine, also known as calamine lotion, is a medication made from powdered calamine (mineral), calamine mineral that is used to treat mild itchiness. Conditions treated include sunburn, insect bites, Toxicodendron radicans, poison ivy, poison oak, and other mild skin conditions. It may also help dry out secretions resulting from skin irritation. It is applied on the skin as a cream (pharmaceutical), cream or lotion. Side effects may include skin irritation. It is considered to be safe in pregnancy. Calamine is a combination of zinc oxide and 0.5% iron(III) oxide, ferric oxide (Fe2O3). The lotion is produced with additional ingredients such as phenol and calcium hydroxide. The use of calamine lotion dates back as far as 1500 BC. It is on the WHO Model List of Essential Medicines, World Health Organization's List of Essential Medicines. Calamine is available over-the-counter as a generic medication. Medical uses Calamine is used to treat itchiness. This includes sunburn, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smithsonite
Smithsonite, also known as zinc spar, is the mineral form of zinc carbonate ( Zn CO3). Historically, smithsonite was identified with hemimorphite before it was realized that they were two different minerals. The two minerals are very similar in appearance and the term calamine has been used for both, leading to some confusion. The distinct mineral smithsonite was named in 1832 by François Sulpice Beudant in honor of English scientist James Smithson (c. 1765–1829), who first identified the mineral in 1802. Smithsonite is a variably colored trigonal mineral which only rarely is found in well formed crystals. The typical habit is as earthy botryoidal masses. It has a Mohs hardness of 4.5 and a specific gravity of 4.4 to 4.5. Smithsonite occurs as a secondary mineral in the weathering or oxidation zone of zinc-bearing ore deposits. It sometimes occurs as replacement bodies in carbonate rocks and as such may constitute zinc ore. It commonly occurs in association with hemimorp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anglesite
Anglesite is a lead sulfate mineral with the chemical formula PbSO4. It occurs as an oxidation product of primary lead sulfide ore, galena. Anglesite occurs as prismatic orthorhombic crystals and earthy masses, and is isomorphous with barite and celestine. It contains 74% of lead by mass and therefore has a high specific gravity of 6.3. Anglesite's color is white or gray with pale yellow streaks. It may be dark gray if impure. It was first recognized as a mineral species by William Withering in 1783, who discovered it in the Parys copper-mine in Anglesey; the name anglesite, from this locality, was given by F. S. Beudant in 1832. The crystals from Anglesey, which were formerly found abundantly on a matrix of dull limonite, are small in size and simple in form, being usually bounded by four faces of a prism and four faces of a dome; they are brownish-yellow in colour owing to a stain of limonite. Crystals from some other localities, notably from in Sardinia, are transparent a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerussite
Cerussite (also known as lead carbonate or white lead ore) is a mineral consisting of lead carbonate with the chemical formula PbCO3, and is an important ore of lead. The name is from the Latin ''cerussa'', white lead. ''Cerussa nativa'' was mentioned by Conrad Gessner in 1565, and in 1832 F. S. Beudant applied the name ''céruse'' to the mineral, whilst the present form, cerussite, is due to W. Haidinger (1845). Miners' names in early use were lead-spar and white-lead-ore. Cerussite crystallizes in the orthorhombic crystal system and is isomorphous with aragonite. Like aragonite it is very frequently twinned, the compound crystals being pseudo-hexagonal in form. Three crystals are usually twinned together on two faces of the prism, producing six-rayed stellate groups with the individual crystals intercrossing at angles of nearly 60°. Crystals are of frequent occurrence and they usually have very bright and smooth faces. The mineral also occurs in compact granular masses, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicification
In geology, silicification is a process in which silica-rich fluids seep into the voids of Earth materials, e.g., rocks, wood, bones, shells, and replace the original materials with silica (SiO2). Silica is a naturally existing and abundant compound found in organic and inorganic materials, including Earth's crust and mantle. There are a variety of silicification mechanisms. In silicification of wood, silica permeates into and occupies cracks and voids in wood such as vessels and cell walls. The original organic matter is retained throughout the process and will gradually decay through time. In the silicification of carbonates, silica replaces carbonates by the same volume. Replacement is accomplished through the dissolution of original rock minerals and the precipitation of silica. This leads to a removal of original materials out of the system. Depending on the structures and composition of the original rock, silica might replace only specific mineral components of the rock ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sericitization
Sericitic alteration or sericitization is a process of mineral alteration caused by hydrothermal fluids invading permeable country rock. Plagioclase feldspar within the rock is converted to sericite (sericite is not a mineral; it is a term that is used to describe any fine-grained white phyllosilicate when a distinction cannot be determined), which typically consists of fine-grained white mica Micas ( ) are a group of silicate minerals whose outstanding physical characteristic is that individual mica crystals can easily be split into fragile elastic plates. This characteristic is described as ''perfect basal cleavage''. Mica is co ... and related minerals. Sericitic alteration occurs within the phyllic alteration zone. Geochemical processes Phyllosilicates {{geochem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloritization
The chlorites are the group of phyllosilicate minerals common in low-grade metamorphic rocks and in altered igneous rocks. Greenschist, formed by metamorphism of basalt or other low-silica volcanic rock, typically contains significant amounts of chlorite. Chlorite minerals show a wide variety of compositions, in which magnesium, iron, aluminium, and silicon substitute for each other in the crystal structure. A complete solid solution series exists between the two most common end members, magnesium-rich clinochlore and iron-rich chamosite. In addition, manganese, zinc, lithium, and calcium species are known. The great range in composition results in considerable variation in physical, optical, and X-ray properties. Similarly, the range of chemical composition allows chlorite group minerals to exist over a wide range of temperature and pressure conditions. For this reason chlorite minerals are ubiquitous minerals within low and medium temperature metamorphic rocks, some igneous ro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrothermal Processes
Metasomatism (from the Greek μετά ''metá'' "change" and σῶμα ''sôma'' "body") is the chemical alteration of a rock by hydrothermal and other fluids. It is traditionally defined as metamorphism which involves a change in the chemical composition, excluding volatile components. It is the replacement of one rock by another of different mineralogical and chemical composition. The minerals which compose the rocks are dissolved and new mineral formations are deposited in their place. Dissolution and deposition occur simultaneously and the rock remains solid. Synonyms of the word ''metasomatism'' are metasomatosis and metasomatic process. The word ''metasomatose'' can be used as a name for specific varieties of metasomatism (for example '' Mg-metasomatose'' and '' Na-metasomatose''). Metasomatism can occur via the action of hydrothermal fluids from an igneous or metamorphic source. In the igneous environment, metasomatism produces skarns, greisen, and may affect hornfels in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
