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Manganocalcite
Manganoan calcite or manganocalcite is a variety of calcite rich in manganese, which gives the mineral a pink color.Manganoan Calcite at Mindat Its chemical formula is . It was first reported from the Mining District, , but is widely distributed around the world, notably in the at Naica, Chihuahua, Mexico as well as in . Mangan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcite
Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on the Mohs scale of mineral hardness, based on Scratch hardness, scratch hardness comparison. Large calcite crystals are used in optical equipment, and limestone composed mostly of calcite has numerous uses. Other polymorphs of calcium carbonate are the minerals aragonite and vaterite. Aragonite will change to calcite over timescales of days or less at temperatures exceeding 300 °C, and vaterite is even less stable. Etymology Calcite is derived from the German , a term from the 19th century that came from the Latin word for Lime (material), lime, (genitive ) with the suffix ''-ite'' used to name minerals. It is thus a Doublet (linguistics), doublet of the word ''wikt:chalk, chalk''. When applied by archaeology, archaeologists and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manganese
Manganese is a chemical element; it has Symbol (chemistry), symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese was first isolated in the 1770s. It is a transition metal with a multifaceted array of industrial alloy uses, particularly in stainless steels. It improves strength, workability, and resistance to wear. Manganese oxide is used as an oxidising agent, as a rubber additive, and in glass making, fertilisers, and ceramics. Manganese sulfate can be used as a fungicide. Manganese is also an essential human dietary element, important in macronutrient metabolism, bone formation, and free radical defense systems. It is a critical component in dozens of proteins and enzymes. It is found mostly in the bones, but also the liver, kidneys, and brain. In the human brain, the manganese is bound to manganese metalloproteins, most notably glutamine synthetase in astrocytes. Manganese is commonly found in labo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Banská Štiavnica
Banská Štiavnica (; ; , ) is a town in central Slovakia, in the middle of an immense caldera created by the collapse of an ancient volcano. For its size, the caldera is known as the Štiavnica Mountains. Banská Štiavnica has a population of less than 10,000. It is a completely preserved medieval town. Because of their historical value, the town and its surroundings were proclaimed by the UNESCO to be a World Heritage Site on December 11, 1993. History The fate of Banská Štiavnica has been closely linked to the exploitation of its abundant resources of silver ore. According to evidence from excavations, the site was settled during the Neolithic period. The first mining settlement was founded by Celts in the 3rd century BC. It was probably occupied by the Celtic Cotini tribe. Roman authors mentioned mining activities of the Cotini, who had lived in present-day central Slovakia until they were deported to Pannonia within the Marcomannic Wars by Rome. The site was also settl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slovak Republic
Slovakia, officially the Slovak Republic, is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the west, and the Czech Republic to the northwest. Slovakia's mostly mountainous territory spans about , hosting a population exceeding 5.4 million. The capital and largest city is Bratislava, while the second largest city is Košice. The Slavs arrived in the territory of the present-day Slovakia in the 5th and 6th centuries. From the late 6th century, parts of modern Slovakia were incorporated into the Avar Khaghanate. In the 7th century, the Slavs played a significant role in the creation of Samo's Empire. When the Avar Khaghanate dissolved in the 9th century, the Slavs established the Principality of Nitra before it was annexed by the Principality of Moravia, which later became Great Moravia. When Great Moravia fell in the 10th century, the territory was integrated into the Principality of Hu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cave Of Swords
The Naica Mine of the Mexican state of Chihuahua, is a lead, zinc and silver mine. Located in Naica in the municipality of Saucillo, the Naica Mine is owned by Industrias Peñoles, the world's largest silver producer. Caverns discovered during mining operations contain gigantic crystals of (calcium sulfate dihydrate, gypsum, also sometimes called selenite. Peñoles announced in October 2015 that it was indefinitely suspending operations due to uncontrollable flooding at the Naica Mine. The peak underground air temperature was 58°C (136°F) with 100% relative humidity, which rapidly exposed the visitors to hyperthermia Hyperthermia, also known as overheating, is a condition in which an individual's body temperature is elevated beyond normal due to failed thermoregulation. The person's body produces or absorbs more heat than it dissipates. When extreme te ... hazard and caused breathing difficulties. Because of the heat, unprotected researchers could only stay up to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naica, Chihuahua
Naica is a town in the Mexican state of Chihuahua. It is located in the municipality of Saucillo. As of 2010, the town of Naica had a population of 4,938, up from 4,775 in the 2005 INEGI Census. It is a mining town and the location of the renowned Naica Mine. See also *Cave of the Crystals Cave of the Crystals or Giant Crystal Cave () is a cave connected to the Naica Mine at a depth of , in Naica, Chihuahua, Mexico. It takes the form of a chamber within the limestone host rock of the mine, and is about long with a volume of . ... References Populated places in Chihuahua (state) Populated places established in 1828 {{Chihuahua-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bulgaria
Bulgaria, officially the Republic of Bulgaria, is a country in Southeast Europe. It is situated on the eastern portion of the Balkans directly south of the Danube river and west of the Black Sea. Bulgaria is bordered by Greece and Turkey to the south, Serbia and North Macedonia to the west, and Romania to the north. It covers a territory of and is the tenth largest within the European Union and the List of European countries by area, sixteenth-largest country in Europe by area. Sofia is the nation's capital and List of cities and towns in Bulgaria, largest city; other major cities include Burgas, Plovdiv, and Varna, Bulgaria, Varna. One of the earliest societies in the lands of modern-day Bulgaria was the Karanovo culture (6,500 BC). In the 6th to 3rd century BC, the region was a battleground for ancient Thracians, Persians, Celts and Ancient Macedonians, Macedonians; stability came when the Roman Empire conquered the region in AD 45. After the Roman state splintered, trib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhodochrosite
Rhodochrosite is a manganese carbonate mineral with chemical composition Manganese(II) carbonate, MnCO3. In its pure form (rare), it is typically a rose-red colour, but it can also be shades of pink to pale brown. It Streak (mineralogy), streaks white, and its Mohs hardness varies between 3.5 and 4.5. Its specific gravity is between 3.45 and 3.6. The crystal system of rhodochrosite is trigonal system, trigonal, with a structure and Cleavage (crystal), cleavage in the carbonate rhombohedral system. The carbonate ions () are arranged in a triangular planar configuration, and the manganese ions (Mn2+) are surrounded by six oxygen ions in an octahedral arrangement. The MnO6 octahedra and CO3 triangles are linked together to form a three-dimensional structure. Crystal twinning is often present. It can be confused with the manganese silicate rhodonite, but is distinctly softer. Rhodochrosite is formed by the oxidation of manganese ore, and is found in South Africa, China, and the Ameri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solid Solution
A solid solution, a term popularly used for metals, is a homogeneous mixture of two compounds in solid state and having a single crystal structure. Many examples can be found in metallurgy, geology, and solid-state chemistry. The word "solution" is used to describe the intimate mixing of components at the atomic level and distinguishes these homogeneous materials from physical mixtures of components. Two terms are mainly associated with solid solutions – ''solvents'' and ''solutes,'' depending on the relative abundance of the atomic species. In general if two compounds are isostructural then a solid solution will exist between the end members (also known as parents). For example sodium chloride and potassium chloride have the same cubic crystal structure so it is possible to make a pure compound with any ratio of sodium to potassium (Na1-xKx)Cl by dissolving that ratio of NaCl and KCl in water and then evaporating the solution. A member of this family is sold under the bra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Minerals
This is a list of minerals which have Wikipedia articles. Minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish the various ''species''. Within a mineral species there may be variation in physical properties or minor amounts of impurities that are recognized by mineralogists or wider society as a mineral ''variety''. Mineral variety names are listed after the valid minerals for each letter. For a more complete listing of all mineral names, see List of minerals recognized by the International Mineralogical Association. A :Varieties that are not valid species: *Adamantine spar (variety of corundum) *Agate (variety of chalcedony and quartz) *Alabaster (variety of gypsum) *Alexandrite (variety of chrysoberyl) *Allingite (synonym of amber) *Alum *Amazonite (variety of microcline) *Amethyst (purple variety of quartz) *Ametrine (variety of quartz) *Ammolite (organic; also a gemstone) *Amos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Delaware
The University of Delaware (colloquially known as UD, UDel, or Delaware) is a Statutory college#Delaware, privately governed, state-assisted Land-grant university, land-grant research university in Newark, Delaware, United States. UD offers four associate's programs, 163 bachelor's programs, 136 master's programs, and 64 doctoral programs across its ten colleges and schools. The main campus is in Newark, with satellite campuses in Dover, Delaware, Dover, Wilmington, Delaware, Wilmington, Lewes, Delaware, Lewes, and Georgetown, Delaware. With 24,221 students , UD is the List of colleges and universities in Delaware, largest university in Delaware by enrollment. UD is Carnegie Classification of Institutions of Higher Education, classified among "R1: Doctoral Universities – Very high research activity". According to the National Science Foundation, UD spent $186 million on research and development in 2018, ranking it 119th in the nation. It is recognized with the Community Enga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
