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Calcium fluoride is a classic example of a crystal with a fluorite structure. Crystallographic information can be collected via x-ray diffraction, providing information on the locations of electron density within a crystal structure. Using modern software such as Olex2, [4] one can solve a crystal structure from crystallographic output files.
Fluorite (also called fluorspar) is the mineral form of calcium fluoride, CaF 2. It belongs to the halide minerals. It crystallizes in isometric cubic habit, although octahedral and more complex isometric forms are not uncommon. The Mohs scale of mineral hardness, based on scratch hardness comparison, defines value 4 as fluorite. [6]
Fluoride is classified as a weak base since it only partially associates in solution, but concentrated fluoride is corrosive and can attack the skin. Fluoride is the simplest fluorine anion . In terms of charge and size, the fluoride ion resembles the hydroxide ion.
Fluorapatite can be synthesized in a three step process. First, calcium phosphate is generated by combining calcium and phosphate salts at neutral pH. This material then reacts further with fluoride sources (often sodium monofluorophosphate or calcium fluoride (CaF 2)) to give the mineral. This reaction is integral in the global phosphorus ...
Naturally occurring CaF 2 is the principal source of hydrogen fluoride, a commodity chemical used to produce a wide range of materials. Calcium fluoride in the fluorite state is of significant commercial importance as a fluoride source. [11] Hydrogen fluoride is liberated from the mineral by the action of concentrated sulfuric acid: [12]
Potassium fluoride is the chemical compound with the formula KF. After hydrogen fluoride , KF is the primary source of the fluoride ion for applications in manufacturing and in chemistry. It is an alkali halide salt and occurs naturally as the rare mineral carobbiite .
Structural and thermodynamic properties of crystal hexagonal calcium apatites, Ca 10 (PO 4) 6 (X) 2 (X= OH, F, Cl, Br), have been investigated using an all-atom Born-Huggins-Mayer potential [42] by a molecular dynamics technique. The accuracy of the model at room temperature and atmospheric pressure was checked against crystal structural data ...
Note: trigonal symmetry is part of the hexagonal group, but not all hexagonal crystals are trigonal. [8]) The silicon atoms of α-(NH 4) 2 [SiF 6] (alpha), have cubic close packing (CCP). The γ form has hexagonal close packing and the β-(NH 4) 2 [SiF 6] has primitive hexagonal packing. [9] In all three phases, 12 fluorine atoms neighbor the ...