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Strontianite
Strontianite (Strontium, SrCarbon, COxygen, O3) is an important raw material for the extraction of strontium. It is a rare carbonate mineral and one of only a few strontium minerals. It is a member of the aragonite group. Aragonite group members: aragonite (CaCO3), witherite (BaCO3), strontianite (SrCO3), cerussite (PbCO3) The ideal formula of strontianite is SrCO3, with molar mass 147.63 g, but calcium (Ca) can substitute for up to 27% of the strontium (Sr) Ion, cations, and barium (Ba) up to 3.3%. The mineral was named in 1791 for the locality, Strontian, Argyllshire, Scotland, where the element strontium had been discovered the previous year. Although good mineral specimens of strontianite are rare, strontium is a fairly common Chemical element, element, with abundance in the Crust (geology), Earth's crust of 370 parts per million by weight, 87 parts per million by Mole (unit), moles, much more common than copper with only 60 parts per million by weight, 19 by moles. Stro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strontium
Strontium is a chemical element; it has symbol Sr and atomic number 38. An alkaline earth metal, it is a soft silver-white yellowish metallic element that is highly chemically reactive. The metal forms a dark oxide layer when it is exposed to air. Strontium has physical and chemical properties similar to those of its two vertical neighbors in the periodic table, calcium and barium. It occurs naturally mainly in the minerals celestine and strontianite, and is mostly mined from these. Both strontium and strontianite are named after Strontian, a village in Scotland near which the mineral was discovered in 1790 by Adair Crawford and William Cruickshank; it was identified as a new element the next year from its crimson-red flame test color. Strontium was first isolated as a metal in 1808 by Humphry Davy using the then newly discovered process of electrolysis. During the 19th century, strontium was mostly used in the production of sugar from sugar beets (see strontian proces ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strontian
Strontian (; ) is the main village in Sunart, an area in western Lochaber, Scottish Highlands, Highland, Scotland, on the A861 road. Prior to 1975 it was part of Argyllshire. It lies on the north shore of Loch Sunart, close to the head of the loch. In the hills to the north of Strontian lead was mined in the 18th century and in these mines the mineral strontianite was discovered, from which the Chemical element, element strontium was first isolated. The village name in Scots Gaelic, Gaelic, ''Sròn an t-Sìthein'', translates as the ''nose'' [i.e. 'point'] ''of the fairy hill'', meaning a knoll or low round hill inhabited by the mythological ''sídhe''. The nearby hamlets of Anaheilt, Bellsgrove, and Upper and Lower Scotstown are now generally considered part of Strontian, with Polloch several miles away on the terminus of the road to Loch Shiel. Strontian is the location of Ardnamurchan High School, the local fire station, police station and other facilities. Geology and m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Celestine (mineral)
Celestine (the IMA-accepted name) or celestite is a mineral consisting of strontium sulfate ( Sr S O). The mineral is named for its occasional delicate blue color. Celestine and the carbonate mineral strontianite are the principal sources of the element strontium, commonly used in fireworks and in various metal alloys. Etymology Celestine derives its name from the Latin word ''caelestis'' meaning celestial which in turn is derived from the Latin word ''caelum'' meaning sky, air, weather, atmosphere and heaven. Occurrence Celestine occurs as crystals, and also in compact massive and fibrous forms. It is mostly found in sedimentary rocks, often associated with the minerals gypsum, anhydrite, and halite. On occasion in some localities, it may also be found with sulfur inclusions. The mineral is found worldwide, usually in small quantities. Pale blue crystal specimens are found in Madagascar. White and orange variants also occurred at Yate, Bristol, UK, where it was ext ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crust (geology)
In geology, the crust is the outermost solid shell of a planet, dwarf planet, or natural satellite. It is usually distinguished from the underlying mantle by its chemical makeup; however, in the case of icy satellites, it may be defined based on its phase (solid crust vs. liquid mantle). The crusts of Earth, Mercury, Venus, Mars, Io, the Moon and other planetary bodies formed via igneous processes and were later modified by erosion, impact cratering, volcanism, and sedimentation. Most terrestrial planets have fairly uniform crusts. Earth, however, has two distinct types: continental crust and oceanic crust. These two types have different chemical compositions and physical properties and were formed by different geological processes. Types of crust Planetary geologists divide crust into three categories based on how and when it formed. Primary crust / primordial crust This is a planet's "original" crust. It forms from solidification of a magma ocean. Toward the end o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystal Structure
In crystallography, crystal structure is a description of ordered arrangement of atoms, ions, or molecules in a crystalline material. Ordered structures occur from intrinsic nature of constituent particles to form symmetric patterns that repeat along the principal directions of three-dimensional space in matter. The smallest group of particles in a material that constitutes this repeating pattern is the unit cell of the structure. The unit cell completely reflects the symmetry and structure of the entire crystal, which is built up by repetitive translation of the unit cell along its principal axes. The translation vectors define the nodes of the Bravais lattice. The lengths of principal axes/edges, of the unit cell and angles between them are lattice constants, also called ''lattice parameters'' or ''cell parameters''. The symmetry properties of a crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unit Cell
In geometry, biology, mineralogy and solid state physics, a unit cell is a repeating unit formed by the vectors spanning the points of a lattice. Despite its suggestive name, the unit cell (unlike a unit vector In mathematics, a unit vector in a normed vector space is a Vector (mathematics and physics), vector (often a vector (geometry), spatial vector) of Norm (mathematics), length 1. A unit vector is often denoted by a lowercase letter with a circumfle ..., for example) does not necessarily have unit size, or even a particular size at all. Rather, the primitive cell is the closest analogy to a unit vector, since it has a determined size for a given lattice and is the basic building block from which larger cells are constructed. The concept is used particularly in describing crystal structure in two and three dimensions, though it makes sense in all dimensions. A lattice can be characterized by the geometry of its unit cell, which is a section of the tiling (a parallelogra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Group
In mathematics, physics and chemistry, a space group is the symmetry group of a repeating pattern in space, usually in three dimensions. The elements of a space group (its symmetry operations) are the rigid transformations of the pattern that leave it unchanged. In three dimensions, space groups are classified into 219 distinct types, or 230 types if chiral copies are considered distinct. Space groups are discrete cocompact groups of isometries of an oriented Euclidean space in any number of dimensions. In dimensions other than 3, they are sometimes called Bieberbach groups. In crystallography, space groups are also called the crystallographic or Fedorov groups, and represent a description of the symmetry of the crystal. A definitive source regarding 3-dimensional space groups is the ''International Tables for Crystallography'' . History Space groups in 2 dimensions are the 17 wallpaper groups which have been known for several centuries, though the proof that the list ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bipyramid
In geometry, a bipyramid, dipyramid, or double pyramid is a polyhedron formed by fusing two Pyramid (geometry), pyramids together base (geometry), base-to-base. The polygonal base of each pyramid must therefore be the same, and unless otherwise specified the base Vertex (geometry), vertices are usually coplanar and a bipyramid is usually ''symmetric'', meaning the two pyramids are mirror images across their common base plane. When each apex (geometry), apex (, the off-base vertices) of the bipyramid is on a line perpendicular to the base and passing through its center, it is a ''right'' bipyramid; otherwise it is ''oblique''. When the base is a regular polygon, the bipyramid is also called ''regular''. Definition and properties A bipyramid is a polyhedron constructed by fusing two Pyramid (geometry), pyramids which share the same polygonal base (geometry), base; a pyramid is in turn constructed by connecting each vertex of its base to a single new vertex (geometry), vertex (th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhombus
In plane Euclidean geometry, a rhombus (: rhombi or rhombuses) is a quadrilateral whose four sides all have the same length. Another name is equilateral quadrilateral, since equilateral means that all of its sides are equal in length. The rhombus is often called a "diamond", after the Diamonds (suit), diamonds suit in playing cards which resembles the projection of an Octahedron#Orthogonal projections, octahedral diamond, or a lozenge (shape), lozenge, though the former sometimes refers specifically to a rhombus with a 60° angle (which some authors call a calisson after calisson, the French sweet—also see Polyiamond), and the latter sometimes refers specifically to a rhombus with a 45° angle. Every rhombus is simple polygon, simple (non-self-intersecting), and is a special case of a parallelogram and a Kite (geometry), kite. A rhombus with right angles is a square. Etymology The word "rhombus" comes from , meaning something that spins, which derives from the verb , roman ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthorhombic Crystal System
In crystallography, the orthorhombic crystal system is one of the 7 crystal systems. Orthorhombic lattices result from stretching a cubic lattice along two of its orthogonal pairs by two different factors, resulting in a rectangular prism with a rectangular base (''a'' by ''b'') and height (''c''), such that ''a'', ''b'', and ''c'' are distinct. All three bases intersect at 90° angles, so the three lattice vectors remain mutually orthogonal In mathematics, orthogonality (mathematics), orthogonality is the generalization of the geometric notion of ''perpendicularity''. Although many authors use the two terms ''perpendicular'' and ''orthogonal'' interchangeably, the term ''perpendic .... Bravais lattices There are four orthorhombic Bravais lattices: primitive orthorhombic, base-centered orthorhombic, body-centered orthorhombic, and face-centered orthorhombic. For the base-centered orthorhombic lattice, the primitive cell has the shape of a right rhombic prism;See , ro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium
Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has a great affinity towards oxygen, passivation (chemistry), forming a protective layer of aluminium oxide, oxide on the surface when exposed to air. It visually resembles silver, both in its color and in its great ability to reflect light. It is soft, magnetism, nonmagnetic, and ductility, ductile. It has one stable isotope, 27Al, which is highly abundant, making aluminium the abundance of the chemical elements, 12th-most abundant element in the universe. The radioactive decay, radioactivity of aluminium-26, 26Al leads to it being used in radiometric dating. Chemically, aluminium is a post-transition metal in the boron group; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state. The aluminium cation Al3+ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
