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It is often combined as a solid solution with hydroxylapatite (Ca 5 (PO 4) 3 OH or Ca 10 (PO 4) 6 (OH) 2) in biological matrices. Chlorapatite (Ca 5 (PO 4 ) 3 Cl) is another related structure. [ 5 ] Industrially, the mineral is an important source of both phosphoric and hydrofluoric acids.
Crystalline Chain carbonate and sulfate minerals: calcite (CaCO 3), dolomite (CaMg(CO 3) 2) and gypsum (CaSO 4 ·2H2O). Amorphous clays: young mixtures of silica (SiO 2-OH) and alumina (Al(OH) 3) which have not had time to form regular crystals. Sesquioxide clays: old, highly leached clays which result in oxides of iron, aluminium and titanium ...
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.
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 ...
Phosphate minerals are minerals that contain the tetrahedrally coordinated phosphate (PO 3− 4) anion, sometimes with arsenate (AsO 3− 4) and vanadate (VO 3− 4) substitutions, along with chloride (Cl −), fluoride (F −), and hydroxide (OH −) anions, that also fit into the crystal structure.
Iron(II) fluoride or ferrous fluoride is an inorganic compound with the molecular formula FeF 2. It forms a tetrahydrate FeF 2 ·4H 2 O that is often referred to by the same names. The anhydrous and hydrated forms are white crystalline solids.
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]
Cubic crystals up to 20 cm across have been found at Dalnegorsk, Russia. [23] The largest documented single crystal of fluorite was a cube 2.12 meters in size and weighing approximately 16 tonnes. [24] Fluorite on barite from the Berbes mine, Ribadesella, Asturias (Spain). Fluorite crystal, 2.2 cm.