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Alkali Feldspar Granite
Alkali feldspar granite, some varieties of which are called 'red granite', is a felsic igneous rock and a type of granite rich in the mineral potassium feldspar (K-spar). It is a dense rock with a phaneritic texture. The abundance of K-spar gives the rock a predominant pink to reddish hue; peppered with minor amounts of black minerals. Chemical composition As shown in the QAPF diagram, alkali feldspar granite contains between 20% - 60% quartz. Less quartz content would lead to "quartz alkali feldspar syenite". More than 90% of the total feldspar content is in the form of alkali feldspar. Less than that amount would designate the rock as a granite. Other incorporated silicate minerals may include, very minor amounts of plagioclase feldspar, mica in the form of muscovite and/or biotite, and amphibole (often hornblende). Oxide minerals such as magnetite, ilmenite, or ulvospinel. Some sulfides and phosphates (mainly apatite) may also be present. Occurrence Alkali feldspar gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystallinity
Crystallinity refers to the degree of structural order in a solid. In a crystal, the atoms or molecules are arranged in a regular, periodic manner. The degree of crystallinity has a large influence on hardness, density, transparency and diffusion. In an ideal gas, the relative positions of the atoms or molecules are completely random. Amorphous materials, such as liquids and glasses, represent an intermediate case, having order over short distances (a few atomic or molecular spacings) but not over longer distances. Many materials, such as glass-ceramics and some polymers, can be prepared in such a way as to produce a mixture of crystalline and amorphous regions. In such cases, crystallinity is usually specified as a percentage of the volume of the material that is crystalline. Even within materials that are completely crystalline, however, the degree of structural perfection can vary. For instance, most metallic alloys are crystalline, but they usually comprise many independent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphibole
Amphibole ( ) is a group of inosilicate minerals, forming prism or needlelike crystals, composed of double chain tetrahedra, linked at the vertices and generally containing ions of iron and/or magnesium in their structures. Its IMA symbol is Amp. Amphiboles can be green, black, colorless, white, yellow, blue, or brown. The International Mineralogical Association currently classifies amphiboles as a mineral supergroup, within which are two groups and several subgroups. Mineralogy Amphiboles crystallize into two crystal systems, monoclinic and orthorhombic. In chemical composition and general characteristics they are similar to the pyroxenes. The chief differences from pyroxenes are that (i) amphiboles contain essential hydroxyl (OH) or halogen (F, Cl) and (ii) the basic structure is a double chain of tetrahedra (as opposed to the single chain structure of pyroxene). Most apparent, in hand specimens, is that amphiboles form oblique cleavage planes (at around 120 degrees), wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithos (journal)
''Lithos'' is a peer review, peer-reviewed academic journal, publishing original research papers on the petrology, geochemistry and petrogenesis of Igneous rock, igneous and Metamorphic rock, metamorphic rocks. Lithos is a hybrid open-access journal and publishes both subscription and open access articles. References English-language journals Geology journals Elsevier academic journals {{geology-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tectonics
Tectonics ( via Latin ) are the processes that result in the structure and properties of the Earth's crust and its evolution through time. The field of ''planetary tectonics'' extends the concept to other planets and moons. These processes include those of orogeny, mountain-building, the growth and behavior of the strong, old cores of continents known as cratons, and the ways in which the relatively rigid tectonic plate, plates that constitute the Earth's outer shell interact with each other. Principles of tectonics also provide a framework for understanding the earthquake and volcanic belts that directly affect much of the global population. Tectonic studies are important as guides for economic geology, economic geologists searching for fossil fuels and ore deposits of metallic and nonmetallic resources. An understanding of tectonic principles can help geomorphology, geomorphologists to explain Erosion and tectonics, erosion patterns and other Earth-surface features. Ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Granite
Granite ( ) is a coarse-grained (phanerite, phaneritic) intrusive rock, intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies underground. It is common in the continental crust of Earth, where it is found in igneous intrusions. These range in size from dike (geology), dikes only a few centimeters across to batholiths exposed over hundreds of square kilometers. Granite is typical of a larger family of ''granitic rocks'', or ''granitoids'', that are composed mostly of coarse-grained quartz and feldspars in varying proportions. These rocks are classified by the relative percentages of quartz, alkali feldspar, and plagioclase (the QAPF diagram, QAPF classification), with true granite representing granitic rocks rich in quartz and alkali feldspar. Most granitic rocks also contain mica or amphibole minerals, though a few (known as leucogranites) conta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syenogranite
Syenogranite is a fine to coarse grained intrusive igneous rock of the same general composition as granite. They are characteristically felsic. The feldspar component of syenogranite is predominantly alkaline in character (usually orthoclase). For example, the syenogranite in the Salmon Mountains in Idaho is pink to tan and composed of 45–55% alkali feldspar, 15–20% plagioclase, 15–20% quartz, 5–8% biotite, 3–5% hornblende, and accessory magnetite (Evans and Green, 2003). Syenogranite is similar to syenite, however the major difference is its higher content of quartz (15-25%) usually at the expense of some alkali feldspar (45-50%), the domination of biotite over hornblende and the presence of muscovite and rutile as additional accessories in the syenogranite. Some syenogranite contain rare idiomorphic amphibole (Fe-hornblende and Fe-edenite), biotite ( annite 25%-35%), plagioclase (An3), along with K-feldspar and quartz. (Mafti, 2001). In the Sao Jose do Campestre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monzogranite
Monzogranite is a plutonic rock that occupies the middle of the QAPF diagram, consisting of between 20–60% quartz, and of the remainder, between 35–65% alkali feldspar and the remainder plagioclase. Examples Pilgangoora belt, Pilbara craton, Western Australia Monzogranite is associated with the Pilbara craton, a terrane that collided with Western Australia approximately 3.315 Ga, forming a greenstone belt. These monzogranites are typically highly fractionated, rich in potassium, poor in aluminum, and have trace element compositions consistent with remelting of an older tonalitic– trondhjemitic– granodioritic crust. Carlindi monzogranites in the same greenstone belt are light greyish-pink coloured, with roughly equal parts plagioclase, quartz, and microcline, and small amounts of muscovite and mafic minerals. The texture of these monzogranites is similar to granodiorite. Quebec's near north In Quebec's near north, early monzogranites are moderately to st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apatite
Apatite is a group of phosphate minerals, usually hydroxyapatite, fluorapatite and chlorapatite, with high concentrations of Hydroxide, OH−, Fluoride, F− and Chloride, Cl− ion, respectively, in the crystal. The formula of the admixture of the three most common Endmember (mineralogy), endmembers is written as Calcium, Ca10(Phosphate, PO4)6(OH,F,Cl)2, and the crystal unit cell formulae of the individual minerals are written as Ca10(PO4)6(OH)2, Ca10(PO4)6F2 and Ca10(PO4)6Cl2. The mineral was named apatite by the German geologist Abraham Gottlob Werner in 1786, although the specific mineral he had described was reclassified as fluorapatite in 1860 by the German mineralogist Karl Friedrich August Rammelsberg. Apatite is often mistaken for other minerals. This tendency is reflected in the mineral's name, which is derived from the Greek word ἀπατάω (apatáō), which means ''to deceive''. Geology Apatite is very common as an accessory mineral in igneous and metamorphic roc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphate Minerals
Phosphates are the naturally occurring form of the element phosphorus. In chemistry, a phosphate is an anion, salt (chemistry), salt, functional group or ester derived from a phosphoric acids and phosphates, phosphoric acid. It most commonly means orthophosphate, a Derivative (chemistry), derivative of orthophosphoric acid, phosphoric acid . The phosphate or orthophosphate ion is derived from phosphoric acid by the removal of three protons . Removal of one proton gives the dihydrogen phosphate ion while removal of two protons gives the hydrogen phosphate ion . These names are also used for salts of those anions, such as ammonium dihydrogen phosphate and trisodium phosphate. File:3-phosphoric-acid-3D-balls.png, Phosphoric acid, Phosphoricacid File:2-dihydrogenphosphate-3D-balls.png, Dihydrogen phosphate, Dihydrogenphosphate File:1-hydrogenphosphate-3D-balls.png, Monohydrogen phosphate, Hydrogenphosphate File:0-phosphate-3D-balls.png, Phosphate or orthophosphate In orga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfide Minerals
The sulfide minerals are a class of minerals containing sulfide (S2−) or disulfide () as the major anion. Some sulfide minerals are economically important as metal ores. The sulfide class also includes the selenides, the tellurides, the arsenides, the antimonides, the bismuthinides, the sulfarsenides and the sulfosalts.http://www.minerals.net/mineral/sort-met.hod/group/sulfgrp.htm Minerals.net Dana Classification, SulfidesKlein, Cornelis and Cornelius S. Hurlbut, Jr., 1986, ''Manual of Mineralogy'', Wiley, 20th ed., pp 269-293 Sulfide minerals are inorganic compounds. Minerals Common or important examples include: * Acanthite * Chalcocite * Bornite *Galena *Sphalerite *Chalcopyrite *Pyrrhotite * Millerite *Pentlandite * Covellite *Cinnabar * Realgar *Orpiment * Stibnite *Pyrite * Marcasite * Molybdenite Sulfarsenides: * Cobaltite * Arsenopyrite * Gersdorffite Sulfosalts: * Pyrargyrite * Proustite * Tetrahedrite * Tennantite * Enargite * B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ilmenite
Ilmenite is a titanium-iron oxide mineral with the idealized formula . It is a weakly magnetic black or steel-gray solid. Ilmenite is the most important ore of titanium and the main source of titanium dioxide, which is used in paints, printing inks, fabrics, plastics, paper, sunscreen, food and cosmetics. Structure and properties Ilmenite is a heavy (specific gravity 4.7), moderately hard (Mohs hardness 5.6 to 6), opaque black mineral with a submetallic luster. It is almost always massive, with thick tabular crystals being quite rare. It shows no discernible cleavage, breaking instead with a conchoidal to uneven fracture. Ilmenite crystallizes in the trigonal system with space group ''R''. The ilmenite crystal structure consists of an ordered derivative of the corundum structure; in corundum all cations are identical but in ilmenite Fe2+ and Ti4+ ions occupy alternating layers perpendicular to the trigonal c axis. Pure ilmenite is paramagnetic (showing only very weak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
