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Khatyrkite
Khatyrkite ( ) is a rare mineral which is mostly composed of copper and aluminium, but may contain up to about 15% of zinc or iron. Its chemical structure is described by an approximate formula or . It was discovered in 1985 in a placer in association with another rare mineral cupalite (). These two minerals have only been found at in the area of the Iomrautvaam, a tributary of the Khatyrka river, in the Koryak Mountains, in Anadyrsky District (former Beringovsky District), Chukotka, Russia. Analysis of one of the samples containing khatyrkite showed that the small rock was from a meteorite. A geological expedition has identified the exact place of the original discovery and found more specimens of the Khatyrka meteorite. The mineral's name derives from the Khatyrka (russian: Хатырка) zone where it was discovered. Its type specimen (defining sample) is preserved in the Mining Museum in Saint Petersburg, and parts of it can be found in other museums, such as Museo d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iomrautvaam
The Iomrautvaam (russian: Иомраутваам; ckt, Емрауткенваам) is a river in Chukotka Autonomous Okrug, Russia. The length of the river is and the area of is drainage basin . The Iomrautvaam is the longest tributary of the Khatyrka river. Course The Iomrautvaam has its source in the Komeutyuyam Range of the Koryak Highlands. It flows in a roughly northeastern direction in the northern section of the range. Finally it meets the right bank of the Khatyrka from its mouth, close to the northeastern end of the ridge. Google Earth Khatyrka meteorite The Khatyrka meteorite, a unique-type of meteorite fell in the area of the Iomrautvaam river basin at . It was found during an expedition to Chukotka in the summer of 2011 buried in a 7,000-year-old layer of dirt and was named Khatyrka meteorite. Flora and fauna The river basin is characterized by tundra vegetation, including mosses, lichens, dwarf shrubs, and sedges.V. Yu. Neshataeva, ''Vegetation cover of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Khatyrka (river)
The Khatyrka (russian: Хатырка; ckt, Ватыркан) is a river in Chukotka Autonomous Okrug, Russia. The length of the river is and the area of is drainage basin . The name of the river comes from the Chukot ''"vatyrkan"'' ''(Ватыркан)'', meaning "dry, depleted place". Course The Khatyrka has its source in the Koryak Highlands. It first flows in an ENE direction along the northern slopes of the Komeutyuyam Range as a mountain river within a narrow valley. It bends to the SSE at the northeastern end of the range and the valley expands, the river dividing into channels. In its lower course it flows along a marshy floodplain. A stretch of the river forms the border with the Olyutorsky District of Kamchatka Krai. Its mouth is in an estuary that is separated by a narrow landspit from the Bering Sea. Khatyrka village lies at the mouth of the estuary. Google Earth Tributaries The main tributary of the Khatyrka is the long Iomrautvaam (Иомраутваам ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Khatyrka Meteorite
Khatyrka (russian: метеорит Хатырка) is a meteorite found in 2011 in the valley of the Iomrautvaam, a tributary of the Khatyrka river, Chukotka Autonomous Okrug, Russian Far East. It is a CV3 (oxidized) chondrite meteorite. History The meteorite had fallen in the Iomrautvaam river basin at and was discovered during an expedition to Chukotka in July 2011. Nine small pieces were found, each less than 1 mm in size, buried in a 7,000-year-old layer of dirt. It was named Khatyrka meteorite.Звизда Т. В., Мануйлов А. А., Василенко А. М. ''Отчет о геологической съемке масштаба 1:50000 и поисках месторождений полезных ископаемых в бассейне нижнего течения р. Иомраутваам на территории листов Р-60-38-В,'' Г; 39-В. Анадырь, 1977. 221 с. Specimens Three representative fragments were deposited at the Department o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Museo Di Storia Naturale Di Firenze
The Museo di Storia Naturale di Firenze is a natural history museum in 6 major collections, located in Florence, Italy. It is part of the University of Florence. Museum collections are open mornings except Wednesday, and all day Saturday; an admission fee is charged. The museum was established on February 21, 1775 by Grand Duke Pietro Leopoldo as the Imperial Regio Museo di Fisica e Storia Naturale. At that time it consisted of several natural history collections housed within the palazzo Torrigiani on Via Romana. Through the past two centuries, it has grown significantly and now forms one of the finest collections in Italy. Collections Today's collections are as follows: * Giardino dei Semplici (Via Micheli, 3) - Europe's third oldest botanical garden, established in 1545, now containing some 9,000 plant specimens. * Museo di Botanica (Via La Pira, 4) - a large herbarium of approximately 4 million specimens, including the historic collections of Andrea Cesalpino (1563), claime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platinum
Platinum is a chemical element with the symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish , a diminutive of "silver". Platinum is a member of the platinum group of elements and group 10 of the periodic table of elements. It has six naturally occurring isotopes. It is one of the rarer elements in Earth's crust, with an average abundance of approximately 5 μg/kg. It occurs in some nickel and copper ores along with some native deposits, mostly in South Africa, which accounts for ~80% of the world production. Because of its scarcity in Earth's crust, only a few hundred tonnes are produced annually, and given its important uses, it is highly valuable and is a major precious metal commodity. Platinum is one of the least reactive metals. It has remarkable resistance to corrosion, even at high temperatures, and is therefore considered a noble metal. Consequent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetragonal Crystal System
In crystallography, the tetragonal crystal system is one of the 7 crystal systems. Tetragonal crystal lattices result from stretching a cubic lattice along one of its lattice vectors, so that the cube becomes a rectangular prism with a square base (''a'' by ''a'') and height (''c'', which is different from ''a''). Bravais lattices There are two tetragonal Bravais lattices: the primitive tetragonal and the body-centered tetragonal. The base-centered tetragonal lattice is equivalent to the primitive tetragonal lattice with a smaller unit cell, while the face-centered tetragonal lattice is equivalent to the body-centered tetragonal lattice with a smaller unit cell. Crystal classes The point groups that fall under this crystal system are listed below, followed by their representations in international notation, Schoenflies notation, orbifold notation, Coxeter notation and mineral examples.Hurlbut, Cornelius S.; Klein, Cornelis, 1985, ''Manual of Mineralogy'', 20th ed., pp. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Point Group
In geometry, a point group is a mathematical group of symmetry operations (isometries in a Euclidean space) that have a fixed point in common. The coordinate origin of the Euclidean space is conventionally taken to be a fixed point, and every point group in dimension ''d'' is then a subgroup of the orthogonal group O(''d''). Point groups are used to describe the symmetries of geometric figures and physical objects such as molecules. Each point group can be represented as sets of orthogonal matrices ''M'' that transform point ''x'' into point ''y'' according to Each element of a point group is either a rotation (determinant of ''M'' = 1), or it is a reflection or improper rotation (determinant of ''M'' = −1). The geometric symmetries of crystals are described by space groups, which allow translations and contain point groups as subgroups. Discrete point groups in more than one dimension come in infinite families, but from the crystallographic restriction theorem and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetragonal
In crystallography, the tetragonal crystal system is one of the 7 crystal systems. Tetragonal crystal lattices result from stretching a cubic lattice along one of its lattice vectors, so that the cube becomes a rectangular prism with a square base (''a'' by ''a'') and height (''c'', which is different from ''a''). Bravais lattices There are two tetragonal Bravais lattices: the primitive tetragonal and the body-centered tetragonal. The base-centered tetragonal lattice is equivalent to the primitive tetragonal lattice with a smaller unit cell, while the face-centered tetragonal lattice is equivalent to the body-centered tetragonal lattice with a smaller unit cell. Crystal classes The point groups that fall under this crystal system are listed below, followed by their representations in international notation, Schoenflies notation, orbifold notation, Coxeter notation and mineral examples.Hurlbut, Cornelius S.; Klein, Cornelis, 1985, ''Manual of Mineralogy'', 20th ed., p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saint Petersburg Mining Institute
Saint Petersburg Mining University (russian: Санкт-Петербургский горный университет), is Russia's oldest technical university, and one of the oldest technical colleges in Europe. It was founded on October 21, 1773, by Empress Catherine the Great, who realised an idea proposed by Peter the Great and Mikhail Lomonosov for training engineers for the mining and metals industries. Having a strong engineering profession was seen by many Russian rulers as a vital means of maintaining Russia's status as a great power. As historian Alfred J. Rieber wrote, "The marriage of technology and central state power had a natural attraction for Peter the Great and his successors, particularly Paul I, Alexander I, and Nicholas I". All three had had a military education and seen the achievements of the engineers of revolutionary and imperial France, who had reconstructed the great highways, unified the waterways and erected buildings throughout Europe in a more las ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Group
In mathematics, physics and chemistry, a space group is the symmetry group of an object in space, usually in three dimensions. The elements of a space group (its symmetry operations) are the rigid transformations of an object that leave it unchanged. In three dimensions, space groups are classified into 219 distinct types, or 230 types if chiral copies are considered distinct. Space groups are discrete cocompact groups of isometries of an oriented Euclidean space in any number of dimensions. In dimensions other than 3, they are sometimes called Bieberbach groups. In crystallography, space groups are also called the crystallographic or Fedorov groups, and represent a description of the symmetry of the crystal. A definitive source regarding 3-dimensional space groups is the ''International Tables for Crystallography'' . History Space groups in 2 dimensions are the 17 wallpaper groups which have been known for several centuries, though the proof that the list was complete was only ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formula Unit
In chemistry, a formula unit is the empirical formula of any ionic or covalent network solid compound used as an independent entity for stoichiometric calculations. It is the lowest whole number ratio of ions represented in an ionic compound. Examples include ionic and and covalent networks such as and C (as diamond or graphite).Steven S. Zumdahl; Susan A. Zumdahl (2000), ''Chemistry'' (5 ed.), Houghton Mifflin, pp. 470-6, Ionic compounds do not exist as individual molecules; a formula unit thus indicates the lowest reduced ratio of ions in the compound. In mineralogy, as minerals are almost exclusively either ionic or network solids, the formula unit is used. The number of formula units (Z) and the dimensions of the crystallographic axes are used in defining the unit cell In geometry, biology, mineralogy and solid state physics, a unit cell is a repeating unit formed by the vectors spanning the points of a lattice. Despite its suggestive name, the unit cell (unlike a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
