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Grossular
Grossular is a calcium-aluminium species of the garnet group of minerals. It has the chemical formula of Ca3Al2(SiO4)3 but the calcium may, in part, be replaced by ferrous iron and the aluminium by ferric iron. The name grossular is derived from the botanical name for the gooseberry, ''grossularia'', in reference to the green garnet of this composition that is found in Siberia. Other shades include cinnamon brown (cinnamon stone variety), red, and yellow. Grossular is a gemstone. In geological literature, grossular has often been called ''grossularite''. Since 1971, however, use of the term grossularite for the mineral has been discouraged by the International Mineralogical Association. Hessonite Hessonite or "cinnamon stone" is a common variety of grossular with the general formula: Ca3Al2Si3O12. The name comes from the grc, ἣσσων (hēssōn), meaning ''inferior''; an allusion to its lower hardness and lower density than most other garnet species varieties. It has a char ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hessonite
Grossular is a calcium-aluminium species of the garnet group of minerals. It has the chemical formula of Ca3Al2(SiO4)3 but the calcium may, in part, be replaced by ferrous iron and the aluminium by ferric iron. The name grossular is derived from the botanical name for the gooseberry, ''grossularia'', in reference to the green garnet of this composition that is found in Siberia. Other shades include cinnamon brown (cinnamon stone variety), red, and yellow. Grossular is a gemstone. In geological literature, grossular has often been called ''grossularite''. Since 1971, however, use of the term grossularite for the mineral has been discouraged by the International Mineralogical Association. Hessonite Hessonite or "cinnamon stone" is a common variety of grossular with the general formula: Ca3Al2Si3O12. The name comes from the grc, ἣσσων (hēssōn), meaning ''inferior''; an allusion to its lower hardness and lower density than most other garnet species varieties. It has a chara ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hessonite Striated Crytals
Grossular is a calcium-aluminium species of the garnet group of minerals. It has the chemical formula of Ca3Al2(SiO4)3 but the calcium may, in part, be replaced by ferrous iron and the aluminium by ferric iron. The name grossular is derived from the botanical name for the gooseberry, ''grossularia'', in reference to the green garnet of this composition that is found in Siberia. Other shades include cinnamon brown (cinnamon stone variety), red, and yellow. Grossular is a gemstone. In geological literature, grossular has often been called ''grossularite''. Since 1971, however, use of the term grossularite for the mineral has been discouraged by the International Mineralogical Association. Hessonite Hessonite or "cinnamon stone" is a common variety of grossular with the general formula: Ca3Al2Si3O12. The name comes from the grc, ἣσσων (hēssōn), meaning ''inferior''; an allusion to its lower hardness and lower density than most other garnet species varieties. It has a chara ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Garnet
Garnets () are a group of silicate minerals that have been used since the Bronze Age as gemstones and abrasives. All species of garnets possess similar physical properties and crystal forms, but differ in chemical composition. The different species are pyrope, almandine, spessartine, grossular (varieties of which are hessonite or cinnamon-stone and tsavorite), uvarovite and andradite. The garnets make up two solid solution series: pyrope-almandine-spessartine (pyralspite), with the composition range ; and uvarovite-grossular-andradite (ugrandite), with the composition range . Etymology The word ''garnet'' comes from the 14th-century Middle English word ''gernet'', meaning 'dark red'. It is borrowed from Old French ''grenate'' from Latin ''granatus,'' from ''granum'' ('grain, seed'). This is possibly a reference to ''mela granatum'' or even ''pomum granatum'' ('pomegranate', ''Punica granatum''), a plant whose fruits contain abundant and vivid red seed covers ( arils), whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nesosilicate
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 polymorphism (materials science), 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 carbonate–silicate cycle, 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 e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mineral
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): Minerals'; p. 1. In the series ''Geology: Landforms, Minerals, and Rocks''. Rosen Publishing Group. The geological definition of mineral normally excludes compounds that occur only in living organisms. However, some minerals are often biogenic (such as calcite) or are organic compounds in the sense of chemistry (such as mellite). Moreover, living organisms often synthesize inorganic minerals (such as hydroxylapatite) that also occur in rocks. The concept of mineral is distinct from rock, which is any bulk solid geologic material that is relatively homogeneous at a large enough scale. A rock may consist of one type of mineral, or may be an aggregate of two or more different types of minerals, spacially segregated into distinct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gooseberry
Gooseberry ( or (American and northern British) or (southern British)) is a common name for many species of ''Ribes'' (which also includes currants), as well as a large number of plants of similar appearance. The berries of those in the genus ''Ribes'' (sometimes placed in the genus ''Grossularia'') are edible and may be green, orange, red, purple, yellow, white, or black. Etymology The ''goose'' in ''gooseberry'' has been mistakenly seen as a corruption of either the Dutch word or the allied German , or of the earlier forms of the French . Alternatively, the word has been connected to the Middle High German ('curl, crisped'), in Latin as . However, the ''Oxford English Dictionary'' takes the more literal derivation from ''goose'' and ''berry'' as probable because "the grounds on which plants and fruits have received names associating them with animals are so often inexplicable that the inappropriateness in the meaning does not necessarily give good grounds for believin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tsavorite
Tsavorite or tsavolite is a variety of the garnet group species grossular, a calcium-aluminium garnet with the formula Ca3 Al2 Si3 O12.Gemological Institute of America, ''GIA Gem Reference Guide'' 1995, Trace amounts of vanadium or chromium provide the green color. In 1967, British gem prospector and geologist Campbell R. Bridges discovered a deposit of green grossular in the mountains of Simanjiro District of Manyara Region of north-east TanzaniaIdar-ObersteinTsavorite International Colored Gemstone Association, accessed online January 24, 2007 in a place called Lemshuko, away from Komolo, the first village. The specimens he found were of very intense color and of high transparency. The find interested the gem trade, and attempts were made to export the stones, but the Tanzanian government did not provide permits. Believing that the deposit was a part of a larger geological structure extending possibly into Kenya, Bridges began prospecting in that nation. He was successful a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zircon
Zircon () is a mineral belonging to the group of nesosilicates and is a source of the metal zirconium. Its chemical name is zirconium(IV) silicate, and its corresponding chemical formula is Zr SiO4. An empirical formula showing some of the range of substitution in zircon is (Zr1–y, REEy)(SiO4)1–x(OH)4x–y. Zircon precipitates from silicate melts and has relatively high concentrations of high field strength incompatible elements. For example, hafnium is almost always present in quantities ranging from 1 to 4%. The crystal structure of zircon is tetragonal crystal system. The natural color of zircon varies between colorless, yellow-golden, red, brown, blue, and green. The name derives from the Persian ''zargun'', meaning "gold-hued". This word is corrupted into "jargoon", a term applied to light-colored zircons. The English word "zircon" is derived from ''Zirkon'', which is the German adaptation of this word. Yellow, orange, and red zircon is also known as "hyacinth", ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthur Herbert Church
Sir Arthur Herbert Church (June 2, 1834 – May 31, 1915) was a British chemist, expert on pottery, stones and chemistry of paintings, who discovered turacin in 1869 and several minerals, including the only British cerium mineral. He was also a talented artist and worked as a professor of chemistry at the Agricultural College in Cirencester and then at the Royal Academy of Arts. He wrote extensively on aspects of chemistry in agriculture, art, and daily life. Early life Church was born in London, the son of John Thomas Church, a solicitor. His studied at King's College London where he showed an interest in both science and art. He spent four years from 1851 to 1855 at the Royal College of Chemistry where he, under A.W. Hofmann, studied alongside William Henry Perkin with whom he published his first research paper. The next four years were spent at Lincoln College, Oxford, where he graduated BA in 1859. He then started a private laboratory in London and beside his chemical analysi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formula
In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship between given quantities. The plural of ''formula'' can be either ''formulas'' (from the most common English plural noun form) or, under the influence of scientific Latin, ''formulae'' (from the original Latin). In mathematics In mathematics, a formula generally refers to an identity which equates one mathematical expression to another, with the most important ones being mathematical theorems. Syntactically, a formula (often referred to as a ''well-formed formula'') is an entity which is constructed using the symbols and formation rules of a given logical language. For example, determining the volume of a sphere requires a significant amount of integral calculus or its geometrical analogue, the method of exhaustion. However, having done t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engraved Gem
An engraved gem, frequently referred to as an intaglio, is a small and usually semi-precious gemstone that has been carved, in the Western tradition normally with images or inscriptions only on one face. The engraving of gemstones was a major luxury art form in the Ancient world, and an important one in some later periods. Strictly speaking, ''engraving'' means carving ''in intaglio'' (with the design cut ''into'' the flat background of the stone), but relief carvings (with the design projecting ''out of'' the background as in nearly all cameos) are also covered by the term. This article uses ''cameo'' in its strict sense, to denote a carving exploiting layers of differently coloured stone. The activity is also called ''gem carving'' and the artists ''gem-cutters''. References to antique gems and intaglios in a jewellery context will almost always mean carved gems; when referring to monumental sculpture, counter-relief, meaning the same as ''intaglio'', is more likely to be use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Mineralogical Association
Founded in 1958, the International Mineralogical Association (IMA) is an international group of 40 national societies. The goal is to promote the science of mineralogy and to standardize the nomenclature of the 5000 plus known mineral species. The IMA is affiliated with the International Union of Geological Sciences (IUGS). The Association supports the activities of Commissions and Working Groups involved on certain aspects of mineralogical practice and facilitates interactions among mineralogists by sponsoring and organising meetings. In particular, the IMA holds its general meeting every four years. The next meeting is scheduled in 2022 in Lyon, France. Presidents The presidents of the IMA have been: * since 2021: Anhuai Lu ** Peking University *2018–2020: Patrick Cordier (born 1961) ** Université de Lille *2016–2018: Peter C. Burns ** University of Notre Dame *2014–2016: Sergey V. Krivovichev (born 1972) ** Saint Petersburg State University *2012–2014: Walter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
