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Optical Mineralogy
Optical mineralogy is the study of minerals and rocks by measuring their optical properties. Most commonly, rock and mineral samples are prepared as thin sections or grain mounts for study in the laboratory with a petrographic microscope. Optical mineralogy is used to identify the mineralogical composition of geological materials in order to help reveal their origin and evolution. Some of the properties and techniques used include: * Refractive index * Birefringence * Michel-Lévy Interference colour chart * Pleochroism * Extinction angle * Conoscopic interference pattern (Interference figure) * Becke line test * Optical relief * Sign of elongation (Length fast vs. length slow) * Wave plate History William Nicol, whose name is associated with the creation of the Nicol prism, is likely the first to prepare thin slices of mineral substances, and his methods were applied by Henry Thronton Maire Witham (1831) to the study of plant petrifactions. This method, of significant im ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leica DMRX
Leica Camera AG () is a German company that manufactures cameras, optical lenses, photographic lenses, binoculars, rifle scopes and microscopes. The company was founded by Ernst Leitz in 1869 (Ernst Leitz Wetzlar), in Wetzlar, Germany. In 1986, the Leitz company changed its name to Leica, due to the fame of the Leica trade-name. The name Leica is derived from the first three letters of the founder's surname (Leitz) and the first two of the word camera: lei-ca (LEItz CAmera). At this time, Leica relocated its factory from Wetzlar to the nearby town of Solms. Leica Camera AG is 55% owned by Austrian investment firm ACM Projektentwicklung GmbH, and 45% owned by The Blackstone Group which licenses the Leica brand name from the Danaher Corporation-owned Leica Microsystems GmbH. History From the year 1907 to the 1950s, the buildings that formed Leica factory were built on Ernst Leitz Street in Wetzlar, and remained until 1986, when the factory was moved to the city of Solms. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wave Plate
A waveplate or retarder is an optical device that alters the polarization state of a light wave travelling through it. Two common types of waveplates are the ''half-wave plate'', which shifts the polarization direction of linearly polarized light, and the ''quarter-wave plate'', which converts linearly polarized light into circularly polarized light and vice versa. A quarter-wave plate can be used to produce elliptical polarization as well. Waveplates are constructed out of a birefringent material (such as quartz or mica, or even plastic), for which the index of refraction is different for light linearly polarized along one or the other of two certain perpendicular crystal axes. The behavior of a waveplate (that is, whether it is a half-wave plate, a quarter-wave plate, etc.) depends on the thickness of the crystal, the wavelength of light, and the variation of the index of refraction. By appropriate choice of the relationship between these parameters, it is possible to introduc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcite
Calcite is a carbonate mineral and the most stable 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 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 ''Calcit'', a term from the 19th century that came from the Latin word for lime, ''calx'' (genitive calcis) with the suffix "-ite" used to name minerals. It is thus etymologically related to chalk. When applied by archaeologists and stone trade professionals, the term alabaster is used not just as in geology and mineralogy, where it is res ... [...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 defini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thin Section Microscopy Siilinjärvi R216 10840 Carbonate
Thin may refer to: * a lean body shape. ''(See also: emaciation, underweight)'' * ''Thin'' (film), a 2006 HBO documentary about eating disorders * Paper Thin (other), referring to multiple songs * Thin (web server), a Ruby web-server based on Mongrel * Thin (name) See also * * * Thin client, a computer in a client-server architecture network. * Thin film, a material layer of about 1 μm thickness. * Thin-film deposition, any technique for depositing a thin film of material onto a substrate or onto previously deposited layers * Thin film memory, high-speed variation of core memory developed by Sperry Rand in a government-funded research project * Thin-film optics, the branch of optics that deals with very thin structured layers of different materials * Thin layer chromatography (TLC), a chromatography technique used in chemistry to separate chemical compounds * Thin layers (oceanography), congregations of phytoplankton and zooplankton in the water column * Thin le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicon Carbide
Silicon carbide (SiC), also known as carborundum (), is a hard chemical compound containing silicon and carbon. A semiconductor, it occurs in nature as the extremely rare mineral moissanite, but has been mass-produced as a powder and crystal since 1893 for use as an abrasive. Grains of silicon carbide can be bonded together by sintering to form very hard ceramics that are widely used in applications requiring high endurance, such as car brakes, car clutches and ceramic plates in bulletproof vests. Large single crystals of silicon carbide can be grown by the Lely method and they can be cut into gems known as synthetic moissanite. Electronic applications of silicon carbide such as light-emitting diodes (LEDs) and detectors in early radios were first demonstrated around 1907. SiC is used in semiconductor electronics devices that operate at high temperatures or high voltages, or both. Natural occurrence Naturally occurring moissanite is found in only minute quantities in cer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micrometres
The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Units (SI) equalling (SI standard prefix "micro-" = ); that is, one millionth of a metre (or one thousandth of a millimetre, , or about ). The nearest smaller common SI unit is the nanometre, equivalent to one thousandth of a micrometre, one millionth of a millimetre or one billionth of a metre (). The micrometre is a common unit of measurement for wavelengths of infrared radiation as well as sizes of biological cells and bacteria, and for grading wool by the diameter of the fibres. The width of a single human hair ranges from approximately 20 to . The longest human chromosome, chromosome 1, is approximately in length. Examples Between 1 μm and 10 μm: * 1–10 μm – length of a typical bacterium * 3–8 μm – width of s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thin Section Scan Crossed Polarizers Siilinjärvi R636-105
Thin may refer to: * a lean body shape. ''(See also: emaciation, underweight)'' * ''Thin'' (film), a 2006 HBO documentary about eating disorders * Paper Thin (other), referring to multiple songs * Thin (web server), a Ruby web-server based on Mongrel * Thin (name) See also * * * Thin client, a computer in a client-server architecture network. * Thin film, a material layer of about 1 μm thickness. * Thin-film deposition, any technique for depositing a thin film of material onto a substrate or onto previously deposited layers * Thin film memory, high-speed variation of core memory developed by Sperry Rand in a government-funded research project * Thin-film optics, the branch of optics that deals with very thin structured layers of different materials * Thin layer chromatography (TLC), a chromatography technique used in chemistry to separate chemical compounds * Thin layers (oceanography), congregations of phytoplankton and zooplankton in the water column * Thin le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David Brewster
Sir David Brewster KH PRSE FRS FSA Scot FSSA MICE (11 December 178110 February 1868) was a British scientist, inventor, author, and academic administrator. In science he is principally remembered for his experimental work in physical optics, mostly concerned with the study of the polarization of light and including the discovery of Brewster's angle. He studied the birefringence of crystals under compression and discovered photoelasticity, thereby creating the field of optical mineralogy.A. D. Morrison-Low (2004) "Brewster, Sir David (1781–1868)" in ''Oxford Dictionary of National Biography'' For this work, William Whewell dubbed him the "father of modern experimental optics" and "the Johannes Kepler of optics." A pioneer in photography, Brewster invented an improved stereoscope, which he called "lenticular stereoscope" and which became the first portable 3D-viewing device. He also invented the stereoscopic camera, two types of polarimeters, the polyzonal lens, the l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henry Clifton Sorby
Henry Clifton Sorby (10 May 1826 – 9 March 1908) was an English microscopist and geologist. His major contribution was the development of techniques for studying iron and steel with microscopes. This paved the way for the mass production of steel. Biography Sorby was born at Woodbourne, near Sheffield in Yorkshire, and attended Sheffield Collegiate School. He early on developed an interest in natural science. One of his first papers related to the excavation of valleys in Yorkshire. In 1847, when he was 21, his father died, leaving him a comfortable private income. He immediately established a scientific laboratory and workshop at his home. He subsequently dealt with the physical geography of former geological periods, with the wave-structure in certain stratified rocks, and the origin of slaty cleavage. He took up the study of rocks and minerals under the microscope, and published an important memoir, "On the Microscopical Structure of Crystals", in 1858 (''Quart. Journ. Geo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petrology
Petrology () is the branch of geology that studies rocks and the conditions under which they form. Petrology has three subdivisions: igneous, metamorphic, and sedimentary petrology. Igneous and metamorphic petrology are commonly taught together because they both contain heavy use of chemistry, chemical methods, and phase diagrams. Sedimentary petrology is, on the other hand, commonly taught together with stratigraphy because it deals with the processes that form sedimentary rock. Background Lithology was once approximately synonymous with petrography, but in current usage, lithology focuses on macroscopic hand-sample or outcrop-scale description of rocks while petrography is the speciality that deals with microscopic details. In the petroleum industry, lithology, or more specifically mud logging, is the graphic representation of geological formations being drilled through and drawn on a log called a mud log. As the cuttings are circulated out of the borehole, they are sam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
