A mineral is, broadly speaking, a solid chemical compound that occurs in pure form. A rock may consist of a single mineral, or may be an aggregate of two or more different minerals, spacially segregated into distinct phases. Compounds that occur only in living beings are excluded, but some minerals are biogenic and/or are organic compounds in the sense of chemistry. Moreover, living beings synthesize inorganic minerals that occur in rocks. In geology and mineralogy, the term "mineral" is reserved for mineral species: crystalline compounds with a well-defined chemical composition and a specific crystal structure. Minerals without a definite crystalline structure, such as opal or obsidian, are more properly called mineraloids. If a chemical compound may occur with different crystal structures, each structure is considered different mineral species. Thus, for example and stishovite are two different minerals consisting of the same compound, silicon dioxide; the International Mineralogical Association is the world's premier standard body for the definition and nomenclature of mineral species.
As of November 2018, the IMA recognizes 5,413 official mineral species. Out of more than 5,500 proposed or traditional ones; the chemical composition of a named mineral species may vary somewhat by the inclusion of small amounts of impurities. Specific varieties of a species sometimes have official names of their own. For example, amethyst is a purple variety of the mineral species quartz; some mineral species can have variable proportions of two or more chemical elements that occupy equivalent positions in the mineral's structure. Sometimes a mineral with variable composition is split into separate species, more or less arbitrarily, forming a mineral group. Besides the essential chemical composition and crystal structure, the description of a mineral species includes its common physical properties such as habit, lustre, colour, tenacity, fracture, specific gravity, fluorescence, radioactivity, as well as its taste or smell and its reaction to acid. Minerals are classified by key chemical constituents.
Silicate minerals comprise 90% of the Earth's crust. Other important mineral groups include the native elements, oxides, carbonates and phosphates. One definition of a mineral encompasses the following criteria: Formed by a natural process. Stable or metastable at room temperature. In the simplest sense, this means. Classical examples of exceptions to this rule include native mercury, which crystallizes at −39 °C, water ice, solid only below 0 °C. Modern advances have included extensive study of liquid crystals, which extensively involve mineralogy. Represented by a chemical formula. Minerals are chemical compounds, as such they can be described by fixed or a variable formula. Many mineral groups and species are composed of a solid solution. For example, the olivine group is described by the variable formula 2SiO4, a solid solution of two end-member species, magnesium-rich forsterite and iron-rich fayalite, which are described by a fixed chemical formula. Mineral species themselves could have a variable composition, such as the sulfide mackinawite, 9S8, a ferrous sulfide, but has a significant nickel impurity, reflected in its formula.
Ordered atomic arrangement. This means crystalline. An ordered atomic arrangement gives rise to a variety of macroscopic physical properties, such as crystal form and cleavage. There have been several recent proposals to classify amorphous substances as minerals; the formal definition of a mineral approved by the IMA in 1995: "A mineral is an element or chemical compound, crystalline and, formed as a result of geological processes." Abiogenic. Biogenic substances are explicitly excluded by the IMA: "Biogenic substances are chemical compounds produced by biological processes without a geological component and are not regarded as minerals. However, if geological processes were involved in the genesis of the compound the product can be accepted as a mineral."The first three general characteristics are less debated than the last two. Mineral classification schemes and their definitions are evolving to match recent advances in mineral science. Recent changes have included the addition of an organic class, in both the new Dana and the Strunz classification schemes.
The organic class includes a rare group of minerals with hydrocarbons. The IMA Commission on New Minerals and Mineral Names adopted in 2009 a hierarchical scheme for the naming and classification of mineral groups and group names and established seven commissions and four working groups to review and classify minerals into an official listing of their published names. According to these new r
Human Development Index
The Human Development Index is a statistic composite index of life expectancy and per capita income indicators, which are used to rank countries into four tiers of human development. A country scores a higher HDI when the lifespan is higher, the education level is higher, the GNI per capita is higher, it was developed by Pakistani economist Mahbub ul Haq, with help from Gustav Ranis of Yale University and Meghnad Desai of the London School of Economics, was further used to measure a country's development by the United Nations Development Program's Human Development Report Office. The 2010 Human Development Report introduced an Inequality-adjusted Human Development Index. While the simple HDI remains useful, it stated that "the IHDI is the actual level of human development", "the HDI can be viewed as an index of'potential' human development"; the index does not take into account several factors, such as the net wealth per capita or the relative quality of goods in a country. This situation tends to lower the ranking for some of the most advanced countries, such as the G7 members and others.
The index is based on the human development approach, developed by ul Haq framed in terms of whether people are able to "be" and "do" desirable things in life. Examples include—Being: well fed, healthy; the freedom of choice is central—someone choosing to be hungry is quite different from someone, hungry because they cannot afford to buy food, or because the country is in a famine. The origins of the HDI are found in the annual Human Development Reports produced by the Human Development Report Office of the United Nations Development Programme; these were devised and launched by Pakistani economist Mahbub ul Haq in 1990, had the explicit purpose "to shift the focus of development economics from national income accounting to people-centered policies". To produce the Human Development Reports, Mahbub ul Haq formed a group of development economists including Paul Streeten, Frances Stewart, Gustav Ranis, Keith Griffin, Sudhir Anand, Meghnad Desai. Nobel laureate Amartya Sen utilized Haq's work in his own work on human capabilities.
Haq believed that a simple composite measure of human development was needed to convince the public and politicians that they can and should evaluate development not only by economic advances but improvements in human well-being. Published on 4 November 2010, the 2010 Human Development Report calculated the HDI combining three dimensions: A long and healthy life: Life expectancy at birth Education index: Mean years of schooling and Expected years of schooling A decent standard of living: GNI per capita In its 2010 Human Development Report, the UNDP began using a new method of calculating the HDI; the following three indices are used: 1. Life Expectancy Index = LE − 20 85 − 20 LEI is 1 when Life expectancy at birth is 85 and 0 when Life expectancy at birth is 20.2. Education Index = MYSI + EYSI 2 2.1 Mean Years of Schooling Index = MYS 15 Fifteen is the projected maximum of this indicator for 2025. 2.2 Expected Years of Schooling Index = EYS 18 Eighteen is equivalent to achieving a master's degree in most countries.3.
Income Index = ln − ln ln − ln II is 1 when GNI per capita is $75,000 and 0 when GNI per capita is $100. The HDI is the geometric mean of the previous three normalized indices: HDI = LEI ⋅ EI ⋅ II 3. LE: Life expectancy at birth MYS: Mean years of schooling EYS: Expected years of schooling GNIpc: Gross national income at purchasing power parity per capita The HDI combined three dimensions last used in its 2009 Report: Life expectancy at birth, as an index of population health and longevity to HDI Knowledge and education, as measured by the adult literacy rate and the combined primary and tertiary gross enrollment ratio. Standard of living, as indicated by the natural logarithm of gross domestic product per capita at purchasing power parity; this methodology was used by the UNDP until their 2011 report. The formula defining the HDI is promulgated by the United Nations Development Programme. In general, to transform a raw variable, say x, into a unit-free index between 0 and 1 (which allo
Mata do Jambreiro Private Natural Heritage Reserve
Mata do Jambreiro Private Natural Heritage Reserve is a state-regulated private natural heritage reserve to the south east of Belo Horizonte, Minas Gerais, Brazil. The reserve contains 912 hectares of seasonal forest in the municipality of Nova Lima in the state of Minas Gerais. There was concern; the Vale mining company therefore leased the area to the government of Minas Gerais for twenty years, while taking responsibility for conservation measures. The Mata do Jambreiro Biological Reserve was established on 26 January 1979 when a special committee was set up to implement the reserve to preserve the local ecology. After the lease expired the mining company regained control, created the Jambreiro Private Natural Heritage Reserve. 912 hectares of high biodiversity continue to be preserved. It is administered by the State Forestry Institute in partnership with the MBR mining company; because it does not meet regulatory requirements, the station is not eligible for the ICMBio Ecological incentives.
The reserve is part of the Southern Environmental Protection Area, certified as a Brazilian biosphere reserve by UNESCO. It lies in the transition zone between the Atlantic Forest biomes. Most of the area was deforested in the first half of the 20th century, the forest has suffered from fires, so much of the vegetation is secondary regrowth. In most of the forest the canopy is 10 to 20 metres high, with emergent trees such as Cariniana estrellensis, Copaifera langsdorffii and Nectandra oppositifolia. Higher up there are stony fields with sparse shrubs such as Lychnophora ericoides and Mimosa calodendron, herbaceous plants such as Pleurothallis teres, Sophronittis crispata, Sophronittis caulescens, Epidendrum secundum and Oncidium gracile; the reserve is home to the Coimbra Filho's titi, southern tamandua, white-throated hummingbird and blue manakin
Gold is a chemical element with symbol Au and atomic number 79, making it one of the higher atomic number elements that occur naturally. In its purest form, it is a bright reddish yellow, soft and ductile metal. Chemically, gold is a group 11 element, it is solid under standard conditions. Gold occurs in free elemental form, as nuggets or grains, in rocks, in veins, in alluvial deposits, it occurs in a solid solution series with the native element silver and naturally alloyed with copper and palladium. Less it occurs in minerals as gold compounds with tellurium. Gold is resistant to most acids, though it does dissolve in aqua regia, a mixture of nitric acid and hydrochloric acid, which forms a soluble tetrachloroaurate anion. Gold is insoluble in nitric acid, which dissolves silver and base metals, a property that has long been used to refine gold and to confirm the presence of gold in metallic objects, giving rise to the term acid test. Gold dissolves in alkaline solutions of cyanide, which are used in mining and electroplating.
Gold dissolves in mercury, forming amalgam alloys. A rare element, gold is a precious metal, used for coinage and other arts throughout recorded history. In the past, a gold standard was implemented as a monetary policy, but gold coins ceased to be minted as a circulating currency in the 1930s, the world gold standard was abandoned for a fiat currency system after 1971. A total of 186,700 tonnes of gold exists above ground, as of 2015; the world consumption of new gold produced is about 50% in jewelry, 40% in investments, 10% in industry. Gold's high malleability, resistance to corrosion and most other chemical reactions, conductivity of electricity have led to its continued use in corrosion resistant electrical connectors in all types of computerized devices. Gold is used in infrared shielding, colored-glass production, gold leafing, tooth restoration. Certain gold salts are still used as anti-inflammatories in medicine; as of 2017, the world's largest gold producer by far was China with 440 tonnes per year.
Gold is the most malleable of all metals. It can be drawn into a monoatomic wire, stretched about twice before it breaks; such nanowires distort via formation and migration of dislocations and crystal twins without noticeable hardening. A single gram of gold can be beaten into a sheet of 1 square meter, an avoirdupois ounce into 300 square feet. Gold leaf can be beaten thin enough to become semi-transparent; the transmitted light appears greenish blue, because gold reflects yellow and red. Such semi-transparent sheets strongly reflect infrared light, making them useful as infrared shields in visors of heat-resistant suits, in sun-visors for spacesuits. Gold is a good conductor of electricity. Gold has a density of 19.3 g/cm3 identical to that of tungsten at 19.25 g/cm3. By comparison, the density of lead is 11.34 g/cm3, that of the densest element, osmium, is 22.588±0.015 g/cm3. Whereas most metals are gray or silvery white, gold is reddish-yellow; this color is determined by the frequency of plasma oscillations among the metal's valence electrons, in the ultraviolet range for most metals but in the visible range for gold due to relativistic effects affecting the orbitals around gold atoms.
Similar effects impart a golden hue to metallic caesium. Common colored gold alloys include the distinctive eighteen-karat rose gold created by the addition of copper. Alloys containing palladium or nickel are important in commercial jewelry as these produce white gold alloys. Fourteen-karat gold-copper alloy is nearly identical in color to certain bronze alloys, both may be used to produce police and other badges. White gold alloys can be made with nickel. Fourteen- and eighteen-karat gold alloys with silver alone appear greenish-yellow and are referred to as green gold. Blue gold can be made by alloying with iron, purple gold can be made by alloying with aluminium. Less addition of manganese, aluminium and other elements can produce more unusual colors of gold for various applications. Colloidal gold, used by electron-microscopists, is red. Gold has only one stable isotope, 197Au, its only occurring isotope, so gold is both a mononuclidic and monoisotopic element. Thirty-six radioisotopes have been synthesized, ranging in atomic mass from 169 to 205.
The most stable of these is 195Au with a half-life of 186.1 days. The least stable is 171Au. Most of gold's radioisotopes with atomic masses below 197 decay by some combination of proton emission, α decay, β+ decay; the exceptions are 195Au, which decays by electron capture, 196Au, which decays most by electron capture with a minor β− decay path. All of gold's radioisotopes with atomic masses above 197 decay by β− decay. At least 32 nuclear isomers have been characterized, ranging in atomic mass from 170 to 200. Within that range, only 178Au, 180Au, 181Au, 182Au, 188Au do not have isomers. Gold's most stable isomer is 198m2Au with a half-life of 2.27 days. Gold's least stable isomer is 177m2Au with a half-life of only 7 ns. 184m1Au has three decay paths: β+ decay, isomeric
Mining is the extraction of valuable minerals or other geological materials from the earth from an ore body, vein, reef or placer deposit. These deposits form a mineralized package, of economic interest to the miner. Ores recovered by mining include metals, oil shale, limestone, dimension stone, rock salt, potash and clay. Mining is required to obtain any material that cannot be grown through agricultural processes, or feasibly created artificially in a laboratory or factory. Mining in a wider sense includes extraction of any non-renewable resource such as petroleum, natural gas, or water. Mining of stones and metal has been a human activity since pre-historic times. Modern mining processes involve prospecting for ore bodies, analysis of the profit potential of a proposed mine, extraction of the desired materials, final reclamation of the land after the mine is closed. De Re Metallica, Georgius Agricola, 1550, Book I, Para. 1Mining operations create a negative environmental impact, both during the mining activity and after the mine has closed.
Hence, most of the world's nations have passed regulations to decrease the impact. Work safety has long been a concern as well, modern practices have improved safety in mines. Levels of metals recycling are low. Unless future end-of-life recycling rates are stepped up, some rare metals may become unavailable for use in a variety of consumer products. Due to the low recycling rates, some landfills now contain higher concentrations of metal than mines themselves. Since the beginning of civilization, people have used stone and metals found close to the Earth's surface; these were used to make early weapons. Flint mines have been found in chalk areas where seams of the stone were followed underground by shafts and galleries; the mines at Grimes Graves and Krzemionki are famous, like most other flint mines, are Neolithic in origin. Other hard rocks mined or collected for axes included the greenstone of the Langdale axe industry based in the English Lake District; the oldest-known mine on archaeological record is the Ngwenya Mine in Swaziland, which radiocarbon dating shows to be about 43,000 years old.
At this site Paleolithic humans mined hematite to make the red pigment ochre. Mines of a similar age in Hungary are believed to be sites where Neanderthals may have mined flint for weapons and tools. Ancient Egyptians mined malachite at Maadi. At first, Egyptians used the bright green malachite stones for ornamentations and pottery. Between 2613 and 2494 BC, large building projects required expeditions abroad to the area of Wadi Maghareh in order to secure minerals and other resources not available in Egypt itself. Quarries for turquoise and copper were found at Wadi Hammamat, Tura and various other Nubian sites on the Sinai Peninsula and at Timna. Mining in Egypt occurred in the earliest dynasties; the gold mines of Nubia were among the largest and most extensive of any in Ancient Egypt. These mines are described by the Greek author Diodorus Siculus, who mentions fire-setting as one method used to break down the hard rock holding the gold. One of the complexes is shown in one of the earliest known maps.
The miners crushed the ore and ground it to a fine powder before washing the powder for the gold dust. Mining in Europe has a long history. Examples include the silver mines of Laurium. Although they had over 20,000 slaves working them, their technology was identical to their Bronze Age predecessors. At other mines, such as on the island of Thassos, marble was quarried by the Parians after they arrived in the 7th century BC; the marble was shipped away and was found by archaeologists to have been used in buildings including the tomb of Amphipolis. Philip II of Macedon, the father of Alexander the Great, captured the gold mines of Mount Pangeo in 357 BC to fund his military campaigns, he captured gold mines in Thrace for minting coinage producing 26 tons per year. However, it was the Romans who developed large scale mining methods the use of large volumes of water brought to the minehead by numerous aqueducts; the water was used for a variety of purposes, including removing overburden and rock debris, called hydraulic mining, as well as washing comminuted, or crushed and driving simple machinery.
The Romans used hydraulic mining methods on a large scale to prospect for the veins of ore a now-obsolete form of mining known as hushing. They built numerous aqueducts to supply water to the minehead. There, the water stored in large tanks; when a full tank was opened, the flood of water sluiced away the overburden to expose the bedrock underneath and any gold veins. The rock was worked upon by fire-setting to heat the rock, which would be quenched with a stream of water; the resulting thermal shock cracked the rock, enabling it to be removed by further streams of water from the overhead tanks. The Roman miners used similar methods to work cassiterite deposits in Cornwall and lead ore in the Pennines; the methods had been developed by the Romans in Spain in 25 AD to exploit large alluvial gold deposits, the largest site being at Las Medulas, where seven long aqueducts tapped local rivers and sluiced the deposits. Spain was one of the most important mining regions, but all regions of the Roman Empire were exploited.
In Great Britain the natives had mined minerals for millennia, but after the Roman conquest, the scale of the operations increased as the Romans needed Britannia's resources gold, silver
Morro Velho called AngloGold Ashanti Brasil Mineração, after its current owner AngloGold Ashanti, is a complex of gold mines located near the city of Nova Lima in the Minas Gerais state of Brazil. It is one of two mining operations of the company in Brazil, the other being the Serra Grande Gold Mine. In 2008, the Brazilian operations contributed 8% to the company's overall production; the mines have been in operation since 1725 and came under the proprietorship of the English Saint John Del Rey Mining Company in 1834. In this period the mine was amongst others instrumental in the establishment of a hydro-electrical power plant, a state of the art hospital, the Villa Nova AC association football team, which had some importance between the 1930s and 1970s and the construction of a circa 10 kilometre tramway line between Nova Lima and Raposos, considered the first in South America. In 1915, the Morro Velho mine reached a vertical depth of 5,824 feet, which made it the deepest mine in the world.
The miners continued going deeper, the mine kept the title of world’s deepest until 1928, when the Village Deep mine in South Africa reached a vertical depth of 8,000 feet, exceeding the depth of the Morro Velho, 7,126 feet in 1929. In 1975 the South Africa based Anglo American Corporation, a precursor to today's AshantiGold, became owners of the operations; these days Morro Velhos is the world's oldest continuously worked mine. Some of the mines' works are over 3,000 meters deep underground. Although Morro Velho's main production is gold, silver and other minerals are extracted at the mining complex. Despite closing of the Minha Velha and Engenho D'Água mines in 2003 and 2004, gold production has increased over the past three years, with 240,000 ounces of gold produced in 2004 at an average recovered ore grade of 0.222 ounces per ton. Cash costs of production totalled $133 per ounce, with the mine realizing adjusted operating profit of $45 million. In 2009, the mine employed close to 2,250 of those being permanent staff.
Recent production figures of the mine were: AngloGold Ashanti website AngloGold Ashanti: Country report Brazil Jolyon Ralph, Ida Chau: Morro Velho mine, Nova Lima, Iron Quadrangle, Minas Gerais, Mindat.org. Augusto Wagner: A fundação do Villa Nova, Arquivo Campeões do Futebol, 2012-06-28. Centro de Memória Morro Velho: Respeito ao passado, referência para o presente e inspiração para inovações futuras. AngloGold Ashanti, 2010
Serra do Rola-Moça State Park
The Serra do Rola-Moça State Park is a state park in the state of Minas Gerais, Brazil. It protects a rugged area in the transition zone between Atlantic Forest. Springs in the park are important to the water supply of Belo Horizonte; the Serra do Rola-Moça State Park is in the metropolitan region of Belo Horizonte, divided between the municipalities of Belo Horizonte, Nova Lima, Ibirité and Brumadinho. It has an area of 3,941.09 hectares. It contains six important springs that supply water to the city, this area is closed to the public; the Serra do Rola-Moça State Park was created by governor Hélio Garcia by decree 36.071 of 27 September 1994. The Taboão, Rola-Moça, Barreiro and Catarina water basins in the park protect the water sources used by the Minas Gerais Sanitation Company. Activities such as leisure and tourism that may interfere with biota in these areas were therefore prohibited, the areas were administered by COPASA/MG; the State Forestry Institute was made responsible for overall administration of the park and for developing plans for administration and environmental education.
The consultative council included representatives of government and civil society organizations. The park is in the transition zone between Atlantic Forest, it contains areas of Atlantic Forest, Alpine tundra and rupestrian ferruginous fields. The ferruginous field vegetation, growing on the iron-bearing "canga" crust, is rare and is found only in the iron quadrilateral of Minas Gerais and in the Carajás Mountains in the state of Pará. Visits to these fields are allowed; the park has diverse flora with species of the Orchidaceae, Bromeliaceae families and jacaranda and cedrus genera. Species include Gochnatia polymorpha and Vellozia squamata; the park provides a refuge for endangered fauna such as the cougar, oncilla, maned wolf, Pampas deer and solitary tinamou. The park is open from 8:00 am to 5:00 pm daily. Camping is not allowed. Access to trails, springs and nurseries requires advance scheduling. At the Nova Lima entrance there is a visitor center with an auditorium for 90 people, meeting rooms and rooms for the environmental police.
At the Barreiro entrance in Belo Horizonte there is an auditorium for 60 people, employee residences and the base of the environmental police. The park has hiking lookouts; the Três Pedras, Jatobá and Morro dos Veados lookouts provide panoramic views. The best time to visit is between April and October, when there is less rain