The granite is dark red, often inclosing veins of quartz, crystallized and compact, and likewise well-formed crystals of schorl.
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Well formed crystals are rare. It has a Mohs hardness of 6.5 and a specific gravity of 2.9. It has a brittle fracture and no cleavage.
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Basaltic magma is formed from lherzolites in the mantle. Once the magma moves out it leaves harzburgites behind in the mantle. However early formed crystals in basaltic magma can also form harzburgite within the mantle.
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Local supersaturation is a common trigger of crystallization, and when the nucleus of the crystalline structure is formed, crystals can self-perpetuate and cause more crystallization and aggregation. Main mechanisms by which the formed crystals and aggregates cause pathological states and ultimately disease are acute necroinflammation, chronic tissue remodelling, and mechanical obstruction. Necroinflammation is an autoamplifying process where crystals are toxic to cells (cytotoxicity) and cause cell death (necrosis and regulated cell death) and a local and systemic inflammatory response. Cytotoxicity includes actin depolymerization, free radical and reactive oxygen species synthesis, and autophagy.
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Lyonsite (Cu3Fe+34(VO4)6) is a rare black vanadate mineral that is opaque with a metallic lustre. It crystallizes in the orthorhombic crystal system. Lyonsite often occurs as small tabular typically well formed crystals. Lyonsite has a good cleavage and a dark gray streak.
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Penetration twins are not unusual. It occurs as well formed crystals and dispersed grains often embedded within gypsum and anhydrite crystals. It has a Mohs hardness of 7 to 7.5 and a specific gravity of 2.9. Refractive index values are nα = 1.658 - 1.662, nβ = 1.662 - 1.667 and nγ = 1.668 - 1.673.
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Most Jedi use naturally formed crystals, whereas Sith tend to use synthetic crystals, which are usually red in color. Although rare, multi-bladed lightsabers can exist, especially among Sith such as Darth Maul's double bladed lightsaber, the Inqusitors' double-bladed/rotating ones, or Kylo Ren's crossguard-bladed one (due to a cracked kyber crystal).
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Nitratine or nitratite, also known as cubic niter (UK: nitre), soda niter or Chile saltpeter (UK: Chile saltpetre), is a mineral, the naturally occurring form of sodium nitrate, NaNO3. Chemically it is the sodium analogue of saltpeter. Nitratine crystallizes in the trigonal system, but rarely occurs as well formed crystals. It is isostructural with calcite.
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The mixture is heated to dissolve the compounds which react with each other as CO2 is drawn off. The solution is then concentrated, excess vanadic acid is removed by filtration, and allowed to cool and crystallize. Since huemulite dissolves easily in water, it can be recrystallized by evaporating the mineral solution. When evaporated slowly, the process creates well-formed crystals up to and .
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Sometimes, shell remains may partially have been preserved. Though it is rare, well-preserved shell material does occur. The parts that were originally filled with sediment are preserved as quartzite; in the air-filled cavities translucent quartz has crystallised, sometimes with well-formed crystals. Depending on mineral inclusions, the colours of the quartzite range from black to pale white over yellowish and pink.
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The mode of burning of the clinker is also important. Clinker rapidly burned at the minimum temperature for combination, then rapidly cooled, contains small, defective crystals that grind easily. These crystals are usually also optimal for reactivity. On the other hand, long burning at excess temperature, and slow cooling, lead to large, well-formed crystals that are hard to grind and un- reactive.
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Peridotites can take on a massive form or may be in layers. Layered peridotites may form the base layers of gabbroic complexes. Even though some layered peridotites appear to have no associated gabbro, they probably once were part of such a complex. Three main textures are found in peridotites: the first are well formed crystals of olivine surrounded by other minerals.
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Wiluite is a dark green, brownish, or black blocky silicate mineral with formula: Ca19(Al,Mg,Fe,Ti)13(B,Al,[ ])5Si18O68(O,OH)10. It has a Mohs hardness of 6 and a specific gravity of 3.36. It has a vitreous lustre, poor cleavage and an irregular brittle fracture. It crystallizes in the tetragonal system and occurs as well-formed crystals with good external form.
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Scheelite is a calcium tungstate mineral with the chemical formula CaWO4. It is an important ore of tungsten (wolfram). Well-formed crystals are sought by collectors and are occasionally fashioned into gemstones when suitably free of flaws. Scheelite has been synthesized using the Czochralski process; the material produced may be used to imitate diamond, as a scintillator, or as a solid-state lasing medium.
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As minerals crystallize, the composition of the residual melt typically changes. If crystals separate from the melt, then the residual melt will differ in composition from the parent magma. For instance, a magma of gabbroic composition can produce a residual melt of granitic composition if early formed crystals are separated from the magma. Gabbro may have a liquidus temperature near 1,200 °C, and the derivative granite-composition melt may have a liquidus temperature as low as about 700 °C.
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Tirrell applies principles from biology and chemistry to polymer synthesis. Recognizing that most synthetic polymers are mixtures, rather than pure substances, he developed pioneering techniques for the creation of precisely-defined polymers of uniform structure. Tirrell and his co-workers have formed crystals, liquid crystals and gels with predetermined, programmable molecular architectures and accompanying properties. His work in macromolecular synthesis underlies the development of "smart" materials, which respond to external cues like temperature, pH, chemical reagents, or light.
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While the majority of quartz crystallizes from molten magma, quartz also chemically precipitates from hot hydrothermal veins as gangue, sometimes with ore minerals like gold, silver and copper. Large crystals of quartz are found in magmatic pegmatites. Well-formed crystals may reach several meters in length and weigh hundreds of kilograms. Naturally occurring quartz crystals of extremely high purity, necessary for the crucibles and other equipment used for growing silicon wafers in the semiconductor industry, are expensive and rare.
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Well-formed crystals are rare, with most of the mineral manifesting in crusts or small reniform aggregates. Erythrite was first described in 1832 for an occurrence in Grube Daniel, Schneeberg, Saxony, and takes its name from the Greek έρυθρος (erythros), meaning red. Historically, erythrite itself has not been an economically important mineral, but the prospector may use it as a guide to associated cobalt and native silver. Erythrite occurs as a secondary mineral in the oxide zone of Co–Ni–As bearing mineral deposits.
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Xenomorph of quartz crystals (grey) in granite In geology, a xenomorph or allotriomorph is a mineral that did not develop its otherwise typical external crystal form because of late crystallization between earlier formed crystals. Xenomorphs are typical of matrix minerals in rapidly crystallizing volcanic lavas and shallow igneous intrusions. It is also typical of the interstitial or cementing minerals formed during the diagenesis of sedimentary rocks. The opposite is an idiomorph in which the external form is controlled only by the internal crystal structure.
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Fractional crystallization is the removal and segregation from a melt of mineral precipitates; except in special cases, removal of the crystals changes the composition of the magma. In essence, fractional crystallization is the removal of early formed crystals from an originally homogeneous magma (for example, by gravity settling) so that these crystals are prevented from further reaction with the residual melt. The composition of the remaining melt becomes relatively depleted in some components and enriched in others, resulting in the precipitation of a sequence of different minerals.Petrology The Study of Igneous...Rocks, Loren A. Raymond, 1995, McGraw-Hill, p.
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Neil Bartlett was born on 15 September 1932 in Newcastle-upon- Tyne, England. Bartlett's interest in chemistry dated back to an experiment at Heaton Grammar School when he was only eleven years old, in which he prepared "beautiful, well-formed" crystals by reaction of aqueous ammonia with copper sulfate. He explored chemistry by constructing a makeshift lab in his parents' home using chemicals and glassware he purchased from a local supply store. He went on to attend King's College, University of Durham (which went on to become Newcastle University) in the United Kingdom where he obtained a Bachelor of Science (1954) and then a doctorate (1958).
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The initial crystallisation of minerals from the magma ocean formed the primordial crust. A potential explanation of this process states the resultant solidification of the mantle edge took place approximately 4.43 Ga. This would subsequently produce continents composed of komatiite, an ultramafic rock rich in magnesium with a high melting point and low dynamic viscosity. Another line of research follows up on this, proposing that differences in the densities of newly formed crystals caused separation of crustal rocks; upper crust largely composed of fractionated gabbros and lower crust composed of anorthosites. The overall result of initial crystallisation formed a primordial crust roughly 60 km in depth.
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Within the field of geology, Bowen's reaction series is the work of the petrologist Norman L. Bowen, who summarized, based on experiments and observations of natural rocks, the sequence of crystallization of common silicate minerals from typical basaltic magma undergoing fractional crystallization (i.e. crystallization wherein early-formed crystals are removed from the magma by crystal settling, leaving behind a liquid of slightly different composition). Bowen's reaction series is able to explain why certain types of minerals tend to be found together while others are almost never associated with one another. He experimented in the early 1900s with powdered rock material that was heated until it melted and then allowed to cool to a target temperature whereupon he observed the types of minerals that formed in the rocks produced.
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