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Sodalite Lake
Sodalite ( ) is a tectosilicate mineral with the formula , with royal blue varieties widely used as an ornamental gemstone. Although massive sodalite samples are opaque, crystals are usually transparent to translucent. Sodalite is a member of the sodalite group with hauyne, nosean, lazurite and tugtupite. First discovered by Europeans in 1811 in the Ilimaussaq intrusive complex in Greenland, sodalite did not become important as an ornamental stone until 1891 when vast deposits of fine material were discovered in Ontario, Canada. Structure The structure of sodalite was first studied by Linus Pauling in 1930. It is a cubic mineral of space group P3n ( space group 218) which consists of an aluminosilicate cage network with Na+ cations and chloride anions in the interframework. (There may be small amounts of other cations and anions instead.) This framework forms a zeolite cage structure. Each unit cell has two cavities, which have almost the same structure as the borate cage fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cubic (crystal System)
In crystallography, the cubic (or isometric) crystal system is a crystal system where the unit cell is in the shape of a cube. This is one of the most common and simplest shapes found in crystals and minerals. There are three main varieties of these crystals: *Primitive cubic (abbreviated ''cP'' and alternatively called simple cubic) *Body-centered cubic (abbreviated ''cI'' or bcc) *Face-centered cubic (abbreviated ''cF'' or fcc, and alternatively called ''cubic close-packed'' or ccp) Each is subdivided into other variants listed below. Although the ''unit cells'' in these crystals are conventionally taken to be cubes, the primitive unit cells often are not. Bravais lattices The three Bravais lattices in the cubic crystal system are: The primitive cubic lattice (cP) consists of one lattice point on each corner of the cube; this means each simple cubic unit cell has in total one lattice point. Each atom at a lattice point is then shared equally between eight adjacent cube ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenland
Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland is the world's largest island. It is one of three constituent countries that form the Kingdom of Denmark, along with Denmark and the Faroe Islands; the citizens of these countries are all citizens of Denmark and the European Union. Greenland's capital is Nuuk. Though a part of the continent of North America, Greenland has been politically and culturally associated with Europe (specifically Norway and Denmark, the colonial powers) for more than a millennium, beginning in 986.The Fate of Greenland's Vikings , by Dale Mackenzie Brown, ''Archaeological Institute of America'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glide Plane
In geometry and crystallography, a glide plane (or transflection) is a symmetry operation describing how a reflection in a plane, followed by a translation parallel with that plane, may leave the crystal unchanged. Glide planes are noted by ''a'', ''b'' or ''c'', depending on which axis the glide is along. If the axis is not defined, then the glide plane may be noted by ''g''. When the glide plane is parallel to the screen, these planes may be indicated by a bent arrow in which the arrowhead indicates the direction of the glide. When the glide plane is perpendicular to the screen, these planes can be represented either by dashed lines when the glide is parallel to the plane of the screen or dotted lines when the glide is perpendicular to the plane of the screen. Additionally, a centered lattice can cause a glide plane to exist in two directions at the same time. This type of glide plane may be indicated by a bent arrow with an arrowhead on both sides when the glide plan is parallel t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Point Groups In Three Dimensions
In geometry, a point group in three dimensions is an isometry group in three dimensions that leaves the origin fixed, or correspondingly, an isometry group of a sphere. It is a subgroup of the orthogonal group O(3), the group of all isometries that leave the origin fixed, or correspondingly, the group of orthogonal matrices. O(3) itself is a subgroup of the Euclidean group E(3) of all isometries. Symmetry groups of geometric objects are isometry groups. Accordingly, analysis of isometry groups is analysis of possible symmetries. All isometries of a bounded (finite) 3D object have one or more common fixed points. We follow the usual convention by choosing the origin as one of them. The symmetry group of an object is sometimes also called its full symmetry group, as opposed to its proper symmetry group, the intersection of its full symmetry group with E+(3), which consists of all ''direct isometries'', i.e., isometries preserving orientation. For a bounded object, the proper sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haüyne
Hauyne or haüyne, also called hauynite or haüynite ( ), is a tectosilicate sulfate mineral with endmember formula . As much as 5 wt % may be present, and also and Cl. It is a feldspathoid and a member of the sodalite group. Hauyne was first described in 1807 from samples discovered in Vesuvian lavas in Monte Somma, Italy,Farndon and Parker (2009). Minerals, Rocks and Fossils of the World. Lorenz Books and was named in 1807 by Brunn-Neergard for the French crystallographer René Just Haüy (1743–1822). It is sometimes used as a gemstone. Sodalite group Formulae: *haüyne *sodalite *nosean *lazurite * tsaregorodtsevite *tugtupite * vladimirivanovite All these minerals are feldspathoids. Haüyne forms a solid solution with nosean and with sodalite. Complete solid solution exists between synthetic nosean and haüyne at 600 °C, but only limited solid solution occurs in the sodalite-nosean and sodalite-haüyne systems.Bellatreccia, Della Ventura, Piccinini, Cav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Applied Crystallography
The ''Journal of Applied Crystallography'' is a peer-reviewed scientific journal published by Wiley-Blackwell on behalf of the International Union of Crystallography. It was established in 1968 and covers the application of crystallography and crystallographic techniques. William Parrish (1914–1991) chaired the committee that started the journal. The ''Journal of Applied Crystallography'' publishes articles on the crystallographic methods that are used to study crystalline and non-crystalline matter with neutrons, X-rays and electrons, their application in condensed matter research, materials science and the life sciences, and their use in identifying phase transformations and structural changes of defects, structure-property relationships, interfaces and surfaces etc. The journal also covers developments in crystallographic instrumentation and apparatus, theory and interpretation and numerical analysis Numerical analysis is the study of algorithms that use numerical approxi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminate
In chemistry, an aluminate is a compound containing an oxyanion of aluminium, such as sodium aluminate. In the naming of inorganic compounds, it is a suffix that indicates a polyatomic ion, polyatomic anion with a central aluminum atom. Aluminate oxyanions Aluminium oxide (alumina) is amphoteric: it dissolves in both bases and acids. When dissolved in bases it forms hydroxyaluminate ions in the same way as aluminium hydroxide or aluminium salts. The hydroxyaluminate or hydrated aluminate can be precipitated and then calcination, calcined to produce anhydrous aluminates. Aluminates are often formulated as a combination of basic oxide and aluminium oxide, for example the formula of anhydrous sodium aluminate NaAlO2 would be shown as Na2O·Al2O3. A number of aluminate oxyanions are known: * The simplest is the approximately tetrahedral found in the compound Na5AlO4, * framework ions in anhydrous sodium aluminate NaAlO2 and monocalcium aluminate, CaAl2O4 made up of corner-sharing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zinc Borate
Zinc borate is an inorganic compound, a borate of zinc. It is a white crystalline or amorphous powder insoluble in water. Its toxicity is low. Its melting point is 980 °C. Variants Several variants of zinc borate exist, differing by the zinc/boron ratio and the water content: * Zinc borate Firebrake ZB (2ZnO·3 B2O3·3.5H2O), CAS number 138265-88-0 * Zinc borate Firebrake 500 (2ZnO·3 B2O3), CAS number 12767-90-7 * Zinc borate Firebrake 415 (4ZnO·B2O3·H2O), CAS number 149749-62-2 * ZB-467 (4ZnO·6B2O3·7H2O), CAS number 1332-07-6 * ZB-223 (2ZnO·2B2O3·3H2O), CAS number 1332-07-6 The hydrated variants lose water between 290–415 °C. Uses Zinc borate is primarily used as a flame retardant in plastics and cellulose fibers, paper, rubbers and textiles. It is also used in paints, adhesives, and pigments. As a flame retardant, it can replace antimony(III) oxide as a synergist in both halogen-based and halogen-free systems. It is an anti-dripping and char-promoting agent, and su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Borate
A borate is any of several boron oxyanions, negative ions consisting of boron and oxygen, such as orthoborate , metaborate , or tetraborate ; or any salt with such anions, such as sodium metaborate, and disodium tetraborate . The name also refers to certain functional groups in molecules consisting of boron and oxygen, and esters with such groups, such as triethyl orthoborate . Natural occurrence Borate ions occur, alone or with other anions, in many borate and borosilicate minerals such as borax, boracite, ulexite (boronatrocalcite) and colemanite. Borates also occur in seawater, where they make an important contribution to the absorption of low frequency sound in seawater. Borates also occur in plants, including almost all fruits. Anions The main borate anions are: * tetrahydroxyborate , found in sodium tetrahydroxyborate . * orthoborate , found in trisodium orthoborate * perborate , as in sodium perborate * metaborate or , found in sodium metaborate * diborate , f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeolite
Zeolites are microporous, crystalline aluminosilicate materials commonly used as commercial adsorbents and catalysts. They mainly consist of silicon, aluminium, oxygen, and have the general formula ･y where is either a metal ion or H+. These positive ions can be exchanged for others in a contacting electrolyte solution. exchanged zeolites are particularly useful as solid acid catalysts. The term ''zeolite'' was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt, who observed that rapidly heating a material, believed to have been stilbite, produced large amounts of steam from water that had been adsorbed by the material. Based on this, he called the material ''zeolite'', from the Greek , meaning "to boil" and , meaning "stone". Zeolites occur naturally but are also produced industrially on a large scale. , 253 unique zeolite frameworks have been identified, and over 40 naturally occurring zeolite frameworks are known. Every new zeolite structure that is ob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
:Category:Minerals In Space Group 218 . ...
Cubic minerals This category lists minerals that display the ''P{{overline, 43n'' (No. 218) space group symmetry of the cubic crystal system In crystallography, the cubic (or isometric) crystal system is a crystal system where the Crystal_structure#Unit_cell, unit cell is in the shape of a cube. This is one of the most common and simplest shapes found in crystals and minerals. There ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
