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Macdonaldite
Macdonaldite is a rare barium silicate mineral with a chemical formula of BaCa4Si16O36(OH)2·10H2O.Alfors, J.T., Stinson, M.C., Matthews, R.A., and Pabst, A. (1965) Seven new barium minerals from eastern Fresno County, California. American Mineralogist, 50, 314-340. Macdonaldite was first described in 1965 and named for Gordon A. Macdonald (1911–1978) an American volcanologist at the University of Hawaii. Macdonaldite crystallises in the orthorhombic system. Macdonaldite is anisotropic with low relief.Bloss, F.D. (1999) Optical Crystallography. Mineralogical Society of America, 5, 161-163. Macdonaldite appears as veins and fracture coatings in a sanbornite Sanbornite is a rare barium phyllosilicate mineral with formula Ba Si2 O5. Sanbornite is a colorless to white to pale green, platey orthorhombic mineral with Mohs hardness of 5 and a specific gravity of 3.74. It was first described from Incli ... and quartz bearing metamorphic rock. Macdonaldite was first describ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phyllosilicate
Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth's crust. In mineralogy, silica (silicon dioxide, ) is usually considered a silicate mineral. Silica is found in nature as the mineral quartz, and its polymorphs. On Earth, a wide variety of silicate minerals occur in an even wider range of combinations as a result of the processes that have been forming and re-working the crust for billions of years. These processes include partial melting, crystallization, fractionation, metamorphism, weathering, and diagenesis. Living organisms also contribute to this geologic cycle. For example, a type of plankton known as diatoms construct their exoskeletons ("frustules") from silica extracted from seawater. The frustules of dead diatoms are a major constituent of deep ocean sediment, and of diatomaceous earth. General structure A silicate mineral is generally an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quartz
Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2. 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 classified as gemstones. Since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings, especially in Eurasia. Quartz is the mineral definin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phyllosilicates
Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth's crust. In mineralogy, silica (silicon dioxide, ) is usually considered a silicate mineral. Silica is found in nature as the mineral quartz, and its polymorphs. On Earth, a wide variety of silicate minerals occur in an even wider range of combinations as a result of the processes that have been forming and re-working the crust for billions of years. These processes include partial melting, crystallization, fractionation, metamorphism, weathering, and diagenesis. Living organisms also contribute to this geologic cycle. For example, a type of plankton known as diatoms construct their exoskeletons ("frustules") from silica extracted from seawater. The frustules of dead diatoms are a major constituent of deep ocean sediment, and of diatomaceous earth. General structure A silicate mineral is g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium Minerals
Calcium is a chemical element with the Symbol (chemistry), symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth's crust, and the third most abundant metal, after iron and aluminium. The most common calcium compound on Earth is calcium carbonate, found in limestone and the fossilised remnants of early sea life; gypsum, anhydrite, fluorite, and apatite are also sources of calcium. The name derives from Latin language, Latin ''calx'' "lime (material), lime", which was obtained from heating limestone. Some calcium compounds were known to the ancients, though their chemistry was unknown until the seventeenth century. Pure calcium was isolated in 1808 via electrolysis of its oxide by Humphry Davy, who named the element. Calcium compounds are wid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barium Minerals
Barium is a chemical element with the symbol Ba and atomic number 56. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, barium is never found in nature as a free element. The most common minerals of barium are baryte (barium sulfate, BaSO4) and witherite (barium carbonate, BaCO3). The name ''barium'' originates from the alchemical derivative "baryta", from Greek (), meaning 'heavy'. ''Baric'' is the adjectival form of barium. Barium was identified as a new element in 1774, but not reduced to a metal until 1808 with the advent of electrolysis. Barium has few industrial applications. Historically, it was used as a getter for vacuum tubes and in oxide form as the emissive coating on indirectly heated cathodes. It is a component of YBCO (high-temperature superconductors) and electroceramics, and is added to steel and cast iron to reduce the size of carbon grains within the microstructure. Barium compounds are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Umbria
it, Umbro (man) it, Umbra (woman) , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = , demographics1_footnotes = , demographics1_title1 = , demographics1_info1 = , demographics1_title2 = , demographics1_info2 = , demographics1_title3 = , demographics1_info3 = , timezone1 = CET , utc_offset1 = +1 , timezone1_DST = CEST , utc_offset1_DST = +2 , postal_code_type = , postal_code = , area_code_type = ISO 3166 code , area_code = IT-55 , blank_name_sec1 = GDP (nominal) , blank_info_sec1 = €22.5 billion (2018) , blank1_name_sec1 = GDP per capita , blank1_info_sec1 = €25,400 (2018) , blank2_name_sec1 = HDI (2018) , blank2_info_sec1 = 0.884 · 12th of 21 , blank_name_sec2 = NUTS Region , blank_info_sec2 = ITE , ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Venanzo
San Venanzo is a ''comune'' (municipality) in the Province of Terni in the Italian region Umbria, located about southwest of Perugia and about northwest of Terni. San Venanzo borders the following municipalities: Ficulle, Fratta Todina, Marsciano, Monte Castello di Vibio, Montegabbione, Orvieto, Parrano, Piegaro, Todi Todi () is a town and ''comune'' (municipality) of the province of Perugia (region of Umbria) in central Italy. It is perched on a tall two-crested hill overlooking the east bank of the river Tiber, commanding distant views in every direction. .... References Cities and towns in Umbria {{Umbria-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tulare County
Tulare County ( ) is a county located in the U.S. state of California. As of the 2020 census, the population was 473,117. The county seat is Visalia. The county is named for Tulare Lake, once the largest freshwater lake west of the Great Lakes. Drained for agricultural development, the site is now in Kings County, which was created in 1893 from the western portion of the formerly larger Tulare County. Tulare County comprises the Visalia- Porterville, CA Metropolitan Statistical Area. The county is located south of Fresno, spanning from the San Joaquin Valley east to the Sierra Nevada. Sequoia National Park is located in the county, as is part of Kings Canyon National Park, in its northeast corner (shared with Fresno County), and part of Mount Whitney, on its eastern border (shared with Inyo County). As of the 2020 census, the population was 473,117, up from 442,179 at the 2010 census. History The land was occupied for thousands of years by the Yokuts. Beginning in the eigh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mariposa County
Mariposa County () is a county in the U.S. state of California. As of the 2020 U.S. Census, the population was 17,131. The county seat is Mariposa. It is located in the western foothills of the Sierra Nevada mountains, north of Fresno, east of Merced, and southeast of Stockton. The county's eastern section is the central portion of Yosemite National Park. There are no incorporated cities in Mariposa County; however, there are communities recognized as census-designated places for statistical purposes. It also has the distinction of having no actual traffic signals anywhere in the county. History Mariposa County was one of the original counties of California, created at the time of statehood in 1850. While it began as the state's largest county, territory that was once part of Mariposa was ceded over time to form all or part of twelve other counties, including all of Merced, Madera, Fresno, Tulare, Kings, and Kern; and parts of San Benito, Mono, Inyo, San Bernardino, and L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fresno County, California
Fresno County (), officially the County of Fresno, is a county located in the central portion of the U.S. state of California. As of the 2020 Census, the population was 1,008,654. The county seat is Fresno, the fifth-most populous city in California. Fresno County comprises the Fresno, CA Metropolitan Statistical Area, which is part of the Fresno- Madera, CA Combined Statistical Area. It is located in the Central Valley, south of Stockton and north of Bakersfield. Since 2010, statewide droughts in California have further strained both Fresno County's and the entire Central Valley's water security. History The area now known as Fresno County was the traditional homeland of Yokuts and Mono peoples, and was later settled by Spaniards during a search for suitable mission sites. In 1846, this area became part of the United States as a result of the Mexican War. Fresno County was formed in 1856 from parts of Mariposa, Merced and Tulare counties. ''Fresno'' is Spanis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphic Rock
Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock ( protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causing profound physical or chemical changes. During this process, the rock remains mostly in the solid state, but gradually recrystallizes to a new texture or mineral composition. The protolith may be an igneous, sedimentary, or existing metamorphic rock. Metamorphic rocks make up a large part of the Earth's crust and form 12% of the Earth's land surface. They are classified by their protolith, their chemical and mineral makeup, and their texture. They may be formed simply by being deeply buried beneath the Earth's surface, where they are subject to high temperatures and the great pressure of the rock layers above. They can also form from tectonic processes such as continental collisions, which cause horizontal pressure, friction, and di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sanbornite
Sanbornite is a rare barium phyllosilicate mineral with formula Ba Si2 O5. Sanbornite is a colorless to white to pale green, platey orthorhombic mineral with Mohs hardness of 5 and a specific gravity of 3.74. It was first described from Incline, Mariposa County, California in 1932Rogers, A.F. (1932) Sanbornite, a new barium silicate mineral from Mariposa County, California. Amer. Mineral., 17, 161-172 and named for mineralogist Frank B. Sanborn (1862–1936). See also *List of minerals *List of minerals named after people This is a list of minerals named after people. The chemical composition follows name. A * Abelsonite: C31H32N4Ni – American physicist Philip Hauge Abelson (1913–2004)alfred * Abswurmbachite: Cu2+Mn3+6O8SiO4 – German mineralogist ... Footnotes ReferencesMindat w/ locations [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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