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Amazonite
Amazonite, also known as Amazonstone, is a green tectosilicate mineral, a variety of the potassium feldspar called microcline. Its chemical formula is KAlSi3O8, which is polymorphic to orthoclase. Its name is taken from that of the Amazon River, from which green stones were formerly obtained, though it is unknown whether those stones were amazonite. Although it has been used for over two thousand years, as attested by archaeological finds in Egypt and Mesopotamia, no ancient or medieval authority mentions it. It was first described as a distinct mineral only in the 18th century.Mikhail Ostrooumov, ''Amazonite: Mineralogy, Crystal Chemistry, and Typomorphism'' (Elsevier, 2016), p. 1-12. Green and greenish-blue varieties of potassium feldspars that are predominantly triclinic are designated as amazonite. It has been described as a "beautiful crystallized variety of a bright verdigris-green" and as possessing a "lively green colour." It is occasionally cut and used as a gemstone. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tibesti Mountains
The Tibesti Mountains are a mountain range in the central Sahara, primarily located in the extreme north of Chad, with a small portion located in southern Libya. The highest peak in the range, Emi Koussi, lies to the south at a height of and is the highest point in both Chad and the Sahara. Bikku Bitti, the highest peak in Libya, is located in the north of the range. The central third of the Tibesti is of volcanic origin and consists of five volcanoes topped by large depressions: Emi Koussi, Tarso Toon, Tarso Voon, Tarso Yega and Toussidé. Major lava flows have formed vast plateaus that overlie Paleozoic sandstone. The volcanic activity was the result of a continental hotspot that arose during the Oligocene and continued in some places until the Holocene, creating fumaroles, hot springs, mud pools and deposits of natron and sulfur. Erosion has shaped volcanic spires and carved an extensive network of canyons through which run rivers subject to highly irregular flows that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microcline
Microcline (KAlSi3O8) is an important igneous rock-forming tectosilicate mineral. It is a potassium-rich alkali feldspar. Microcline typically contains minor amounts of sodium. It is common in granite and pegmatites. Microcline forms during slow cooling of orthoclase; it is more stable at lower temperatures than orthoclase. Sanidine is a polymorph of alkali feldspar stable at yet higher temperature. Microcline may be clear, white, pale-yellow, brick-red, or green; it is generally characterized by cross-hatch twinning that forms as a result of the transformation of monoclinic orthoclase into triclinic microcline. The chemical compound name is potassium aluminium silicate, and it is known as E number reference E555. Geology Microcline may be chemically the same as monoclinic orthoclase, but because it belongs to the triclinic crystal system, the prism angle is slightly less than right angles; hence the name "microcline" from the Greek "small slope." It is a fully ordered tricl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tectosilicate
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] |
Granitoid
A granitoid is a generic term for a diverse category of coarse-grained igneous rocks that consist predominantly of quartz, plagioclase, and alkali feldspar. Granitoids range from plagioclase-rich tonalites to alkali-rich syenites and from quartz-poor monzonites to quartz-rich quartzolites. As only two of the three defining mineral groups (quartz, plagioclase, and alkali feldspar) need to be present for the rock to be called a granitoid, foid-bearing rocks, which predominantly contain feldspars but no quartz, are also granitoids. The terms ''granite'' and ''granitic rock'' are often used interchangeably for granitoids; however, granite is just one particular type of granitoid. Granitoids are diverse; no classification system for granitoids can give a complete and unique characterization of the origin, compositional evolution, and geodynamic environment for the genesis of a granitoid. Accordingly, multiple granitoid classification systems have been developed such as those based on: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arapahoe County, Colorado
Arapahoe County ( ) is a county located in the U.S. state of Colorado. As of the 2020 census, its population was 655,070, making it the third-most populous county in Colorado. The county seat is Littleton, and the most populous city is Aurora. The county was named for the Arapaho Native American tribe, who once lived in the region. Arapahoe County is part of the Denver-Aurora- Lakewood metropolitan statistical area. Arapahoe County calls itself "Colorado's First County", since its origins antedate the Pike's Peak Gold Rush. History On August 25, 1855, the Kansas Territorial Legislature created a huge Arapahoe County to govern the entire western portion of the Territory of Kansas. The county was named for the Arapaho Nation, who lived in the region. In July 1858, gold was discovered along the South Platte River in Arapahoe County (in present-day Englewood). This discovery precipitated the Pike's Peak Gold Rush. Many residents of the mining region felt disconnected from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deer Trail, Colorado
The Town of Deer Trail is a Statutory Town located in eastern Arapahoe County, Colorado, United States. The town population was 1,068 at the 2020 United States Census, a +95.60% increase since the 2010 United States Census. Deer Trail is a part of the Denver–Aurora–Lakewood, CO Metropolitan Statistical Area and the Front Range Urban Corridor. The town is situated along Interstate 70, approximately east of Denver. History Deer Trail was founded when the Kansas Pacific Railway built a station in what is now Deer Trail in 1870. The town was platted by the railway in 1875 and soon became a shipping point for grain, livestock, and eggs. By the late 1920s Deer Trail grew into a town larger than it is today with two banks, five grocery stores, and three hotels. The Great Depression of the 1930s took a major toll on the town's economy, and a further blow took place in June 1965 when a devastating flood destroyed or severely damaged the businesses along main street. Many of these bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Almqvist & Wiksell
Almqvist & Wiksell is a former Swedish printing and publishing company. Since 1990 it is a trademark owned by the publishing company Liber. Almqvist & Wiksell originated from the acquisition of the Uppsala company Edquist & Berglunds tryckeri by Robert Almqvist (1857–1938) and Julius Wiksell (1855–1897).Nationalencyklopedin ''Nationalencyklopedin'' (; "The National Encyclopedia" in English), abbreviated NE, is a comprehensive contemporary Swedish-language encyclopedia, initiated by a favourable loan from the Government of Sweden of 17 million Swedish kronor in 1 ..., Almqvist & Wiksell Tryckeri AB. http://www.ne.se/uppslagsverk/encyklopedi/lång/almqvist-wiksell-tryckeri-ab (retrieved 02-09-2022) References Book publishing companies of Sweden Mass media in Uppsala Publishing companies established in 1882 1882 establishments in Sweden {{publish-company-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Västra Götaland County
Västra Götaland County ( sv, Västra Götalands län) is a county or '' län'' on the western coast of Sweden. The county is the second most populous of Sweden's counties and it comprises 49 municipalities (''kommuner''). Its population of 1,616,000 amounts to 17% of Sweden's population. The formal capital and seat of the governor of Västra Götaland County is Gothenburg. The political capital and seat of the Västra Götaland Regional Council is Vänersborg. The county was established on 1 January 1998, when Älvsborg County, Gothenburg and Bohus County and Skaraborg County were merged. Provinces Sweden's counties are generally of greater importance than its provinces. The counties are the main administrative units for politics and population census counts. Due to its size and young age, the Västra Götaland County has no common heritage. Of cultural and historical significance are the provinces that Västra Götaland County consists of: Västergötland, Bohusl� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skuleboda
Skuleboda ( sv, Skuleboda kvartsfältspatbrott) was a quartz and feldspar mine near Vänersborg, in western Sweden. Mining at Skuleboda begun in 1927, then halted the same year and continued again from 1931 to 1934. The mined deposit is a pegmatite with a length of 45 m and a maximum width of 10 m. It contains amazonite Amazonite, also known as Amazonstone, is a green tectosilicate mineral, a variety of the potassium feldspar called microcline. Its chemical formula is KAlSi3O8, which is polymorphic to orthoclase. Its name is taken from that of the Amazon Rive ... feldspar. Rare occurrences of yttrotantalite has been found in the mined pegmatite. References {{Reflist 1927 establishments in Sweden 1934 disestablishments in Sweden Feldspar mines in Sweden Quartz mines in Sweden Vänersborg Municipality Former mines in Sweden ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceres, Western Cape
Ceres is the administrative centre and largest town of the Witzenberg Local Municipality in the Western Cape Province of South Africa. Ceres serves as a regional centre for the surrounding towns of Wolseley, Tulbagh, Op-die-Berg and Prince Alfred Hamlet. It is situated in the ''Warmbokkeveld'' (Afrikaans: "warm antelope field") Valley about 170 km north-east of Cape Town. Ceres is located at the north-eastern entrance to Michell's Pass and was the old route north between Cape Town and Johannesburg, which was later replaced by the N1 highway, which traverses the Breede River Valley to the south. Named after the Roman goddess of agriculture, Ceres, a name which is fitting as the valley in which the town is situated is extremely fertile and is a major producer of South Africa's deciduous fruit. Geography and climate Ceres experiences a typical Mediterranean climate tempered by its altitude. The town experiences warmer temperatures in summer, due to its inland location wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kakamas
Kakamas is a town founded in 1898 and located in the Northern Cape province of South Africa, on the banks of the Orange River. Originated as at a place where the Orange River could be relatively easily crossed. The spot was first known as Bassonsdrif. In 1898 a proper settlement was established and under the auspices of the Dutch Reformed Church the area was developed as an agricultural spot. It became a municipality in 1954. History The small town of Kakamas was built on the sheer hard work and determination of a couple of impoverished stock farmers at the end of the 19th century. The drought of 1895–97 was followed by an outbreak of rinderpest, leaving many farmers destitute. In 1897, the Dutch Reformed Church started a "colony" on the farms Soetap and Kakamas on the banks of the Orange River for white people who had lost everything as a result of the drought. Ignoring the criticism of qualified engineers about their building methods, the farmers continued to construct t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Khâi-Ma Local Municipality
Khâi-Ma is an administrative area in the Namakwa District of Northern Cape in South Africa. Khai-Ma is a Khoi word meaning "to stand up". Main places The 2011 census divided the municipality into the following main places: Politics The municipal council consists of eleven members elected by mixed-member proportional representation. Six councillors are elected by first-past-the-post voting in six wards, while the remaining five are chosen from party lists so that the total number of party representatives is proportional to the number of votes received. In the election of 1 November 2021 the African National Congress The African National Congress (ANC) is a social-democratic political party in South Africa. A liberation movement known for its opposition to apartheid, it has governed the country since 1994, when the first post-apartheid election install ... (ANC) won a majority of six seats on the council. The following table shows the results of the election. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
