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Itabirite
Itabirite, also called banded-quartz hematite or hematite schist, is a foliated, metamorphosed oxide-facies iron formation in which the original chert or jasper bands have been recrystallized into macroscopically distinguishable grains of quartz and the iron is present as thin layers of hematite, magnetite, or martite (pseudomorphs of hematite after magnetite). The term was originally applied in Itabirito (Pico de Itabirito), in the state of Minas Gerais and southern part of Belo Horizonte, Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ..., to a high-grade, massive specular hematite ore (66% iron) associated with a schistose rock composed of granular quartz and scaly hematite. The term is now widely used outside Brazil. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belo Horizonte
Belo Horizonte is the List of largest cities in Brazil, sixth-largest city in Brazil, with a population of around 2.3 million, and the third largest metropolitan area, containing a population of 6 million. It is the List of cities in South America, 13th-largest city in South America and the Largest cities in the Americas, 18th-largest in the Americas. The metropolis is anchor to the Greater Belo Horizonte, Belo Horizonte metropolitan area, ranked as the List of metropolitan areas in Brazil, third most populous metropolitan area in Brazil and the List of metropolitan areas in the Americas, 17th most populous in the Americas. Belo Horizonte is the capital of States of Brazil, the state of Minas Gerais, Brazil's List of Brazilian states by population, second-most populous state. It is the first planned modern city in Brazil. The region was first settled in the early 18th century, but the city as it is known today was planned and constructed in the 1890s to replace Ouro Preto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hematite
Hematite (), also spelled as haematite, is a common iron oxide compound with the formula, Fe2O3 and is widely found in rocks and soils. Hematite crystals belong to the rhombohedral lattice system which is designated the alpha polymorph of . It has the same crystal structure as corundum () and ilmenite (). With this it forms a complete solid solution at temperatures above . Hematite occurs naturally in black to steel or silver-gray, brown to reddish-brown, or red colors. It is mined as an important ore mineral of iron. It is electrically conductive. Hematite varieties include ''kidney ore'', ''martite'' ( pseudomorphs after magnetite), ''iron rose'' and ''specularite'' ( specular hematite). While these forms vary, they all have a rust-red streak. Hematite is not only harder than pure iron, but also much more brittle. The term ''kidney ore'' may be broadly used to describe botryoidal, mammillary, or reniform hematite. Maghemite is a polymorph of hematite (γ-) with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudomorph
In mineralogy, a pseudomorph is a mineral or mineral compound that appears in an atypical form (crystal system), resulting from a substitution process in which the appearance and dimensions remain constant, but the original mineral is replaced by another due to alteration, or chemical substitution, dissolution and refilling, structural changes or incrustation. The name literally means "false form". Terminology for pseudomorphs is "''replacer'' after ''original''", as in ''brookite'' after ''rutile''. The term ''pseudomorphoses'' was initially used by Haüy. Substitution pseudomorph A substitution pseudomorph is a pseudomorph in which one mineral or other material is replaced by another. The original shape of the mineral remains unchanged, but chemical composition, color, hardness, and other properties change to those of the replacing mineral. This happens typically when a mineral of one composition changes by chemical reaction to another of similar composition, retaining t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of Brazil
The geology of Brazil includes very ancient craton basement rock from the Precambrian overlain by sedimentary rocks and intruded by igneous activity, as well as impacted by the rifting of the Atlantic Ocean. Geologic history, stratigraphy, and tectonics Much of the rock underlying Brazil formed during the Precambrian, including the São Francisco craton, São Francisco Craton which outcrops in Minas Gerais and Bahia. In the Mesoproterozoic, the Rio de la Plata Craton (beneath southern Brazil), the vast Amazonia Craton, and the small São Luis Craton and sections of the Congo Craton which form the basement rock of much of Brazil were joined with Africa. Earlier, during the Archean, the São Francisco Craton developed between 3.2 and 2.6 billion years ago and grew as microcontinents collided with it, forming a series of mobile belts. The rocks became a craton, a section of stable continental crust by the end of the Transamazonian orogeny, Trans-amazonian orogeny 1.8 bill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schistose
Schist ( ) is a medium-grained metamorphic rock generally derived from fine-grained sedimentary rock, like shale. It shows pronounced ''schistosity'' (named for the rock). This means that the rock is composed of mineral grains easily seen with a low-power hand lens, oriented in such a way that the rock is easily split into thin flakes or plates. This texture reflects a high content of platy minerals, such as mica, talc, chlorite, or graphite. These are often interleaved with more granular minerals, such as feldspar or quartz. Schist typically forms during regional metamorphism accompanying the process of mountain building (orogeny) and usually reflects a medium grade of metamorphism. Schist can form from many different kinds of rocks, including sedimentary rocks such as mudstones and igneous rocks such as tuffs. Schist metamorphosed from mudstone is particularly common and is often very rich in mica (a ''mica schist''). Where the type of the original rock (the protolith) is discern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brazil
Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population, seventh-largest by population, with over 212 million people. The country is a federation composed of 26 Federative units of Brazil, states and a Federal District (Brazil), Federal District, which hosts the capital, Brasília. List of cities in Brazil by population, Its most populous city is São Paulo, followed by Rio de Janeiro. Brazil has the most Portuguese-speaking countries, Portuguese speakers in the world and is the only country in the Americas where Portuguese language, Portuguese is an Portuguese-speaking world, official language. Bounded by the Atlantic Ocean on the east, Brazil has a Coastline of Brazil, coastline of . Covering roughly half of South America's land area, it Borders of Brazil, borders all other countries and ter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minas Gerais
Minas Gerais () is one of the 27 federative units of Brazil, being the fourth largest state by area and the second largest in number of inhabitants with a population of 20,539,989 according to the 2022 Brazilian census, 2022 census. Located in the Southeast Region, Brazil, Southeast Region of the country, it is bordered to south and southwest by São Paulo (state), São Paulo; Mato Grosso do Sul to the west; Goiás and the Federal District (Brazil), Federal District to the northwest; Bahia to the north and northeast; Espírito Santo to the east; and Rio de Janeiro (state), Rio de Janeiro to the southeast. The state's capital and largest city, Belo Horizonte, is a major urban and finance center in Brazil, being the List of largest cities in Brazil#Top 115 most populous cities and state capitals, sixth most populous municipality in the country while its Greater Belo Horizonte, metropolitan area ranks as the List of metropolitan areas in Brazil, third largest in Brazil with just ov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Itabirito
Itabirito is a Municipalities of Brazil, municipality in the Minas Gerais state of Brazil. Its population is estimated to have 52,446 people in 2020. The city belongs to the mesoregion Metropolitan of Belo Horizonte and to the microregion of Ouro Preto. The municipality contains 10% of the Serra do Gandarela National Park, created in 2014. During the 19th century, there was a high influx of immigration to Itabirito, caused both by gold mining and the construction of the railroad. Notable people Telê Santana (1931–2006), soccer coach (sport), coach of the Brazilian professional team during the 1982 World Cup and 1986 World Cup editions. He is regarded as one of the greatest innovators in the history of Brazilian soccer. Itabirito on the Map Satellite image of Itabirito (Google Earth) http://maps.google.ca/maps?f=q&hl=en&geocode=&q=Itabirito&sll=-19.147763,-41.726074&sspn=1.849915,2.570801&ie=UTF8&t=h&z=11&om=1 Mayors of Itabirito José Theodoro Alves Júnior (1923–193 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Bureau Of Mines
The United States Bureau of Mines (USBM) was the primary Federal government of the United States, United States government agency in the 20th century that conducted scientific research and disseminated information on the extraction, processing, use, and conservation of mineral natural resource, resources. The Bureau was abolished in 1996. History The U.S. Bureau of Mines was established in the United States Department of the Interior, U.S. States Department of the Interior on May 16, 1910, pursuant to the Organic Act (Public Law 179), to deal with a wave of catastrophic Mining, mine disasters. The Bureau's mission was gradually expanded to include: * The conduct of research to enhance the safety, health, and environmental impact of mining and processing of minerals and materials. * The collection, analysis, and dissemination of information about mining and processing of more than 100 mineral commodities across the Nation and in more than 185 countries around the world. * Analy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetite
Magnetite is a mineral and one of the main iron ores, with the chemical formula . It is one of the iron oxide, oxides of iron, and is ferrimagnetism, ferrimagnetic; it is attracted to a magnet and can be magnetization, magnetized to become a permanent magnet itself. With the exception of extremely rare native iron deposits, it is the most magnetic of all the naturally occurring minerals on Earth. Naturally magnetized pieces of magnetite, called lodestone, will attract small pieces of iron, which is how ancient peoples first discovered the property of magnetism. Magnetite is black or brownish-black with a metallic luster, has a Mohs scale of mineral hardness, Mohs hardness of 5–6 and leaves a black streak (mineralogy), streak. Small grains of magnetite are very common in igneous rocks, igneous and metamorphic rocks. The chemical IUPAC name is iron(II,III) oxide and the common chemical name is ''ferrous-ferric oxide''. Properties In addition to igneous rocks, magnetite als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schist
Schist ( ) is a medium-grained metamorphic rock generally derived from fine-grained sedimentary rock, like shale. It shows pronounced ''schistosity'' (named for the rock). This means that the rock is composed of mineral grains easily seen with a low-power hand lens, oriented in such a way that the rock is easily split into thin flakes or plates. This texture (geology), texture reflects a high content of platy minerals, such as mica, talc, chlorite group, chlorite, or graphite. These are often interleaved with more granular minerals, such as feldspar or quartz. Schist typically forms during regional metamorphism accompanying the process of mountain building (orogeny) and usually reflects a medium Metamorphism#Metamorphic grades, grade of metamorphism. Schist can form from many different kinds of rocks, including sedimentary rocks such as mudstones and igneous rocks such as tuffs. Schist metamorphosed from mudstone is particularly common and is often very rich in mica (a ''mica schis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quartz
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of Silicon dioxide, SiO2. Quartz is, therefore, classified structurally as a Silicate mineral#Tectosilicates, framework silicate mineral and compositionally as an oxide mineral. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar. Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are chiral. The transformation from α-quartz to β-quartz takes place abruptly at . Since the transformation is accompanied by a significant change in volume, it can easily induce microfracturing of ceramics or rocks passing through this temperature threshold. There are many different varieties of quartz, several of which are classifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
