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Formula (repeating unit) CaF 2: IMA symbol: Flr [1] Strunz classification: 3.AB.25: ... Fluorite (also called fluorspar) is the mineral form of calcium fluoride, CaF 2.
The fluorite structure refers to a common motif for compounds with the formula MX 2. [1] [2] The X ions occupy the eight tetrahedral interstitial sites whereas M ions occupy the regular sites of a face-centered cubic (FCC) structure. Many compounds, notably the common mineral fluorite (CaF 2), adopt this structure.
Some sources give unit cell parameters for one formula unit per unit cell (Z = 1), but some scientists consider the formula to be half the value accepted by the International Mineralogical Association (IMA), i.e. Ca 5 ((Si,S)O 4)) 3 F, with two formula units per unit cell (Z = 2). Cell parameters for natural, as opposed to synthetic, material ...
Formula (repeating unit) Be 4 Si 2 O 7 (OH) 2: IMA symbol: Btd [1] Strunz classification: ... tourmaline, muscovite, fluorite and quartz. [2] It, with beryl, are ores ...
Formula (repeating unit) FeS 2: IMA symbol: Mrc [1] Strunz classification: 2.EB.10a: ... sphalerite, fluorite, dolomite, and calcite. [3] As a primary mineral ...
Its chemical formula is (Na,Ca) 2 Ta 2 O 6 (O,OH,F). Today [ when? ] it is a name of a group of oxide minerals of a similar stoichiometry having tantalum prevailing over titanium and niobium. The microlite group belongs to a large pyrochlore supergroup that occurs in pegmatites and constitutes an ore of tantalum.
The chemical composition which was given by Tschermak in 1884 for this dravite approximately corresponds to the formula NaMg 3 (Al,Mg) 6 B 3 Si 6 O 27 (OH), which is in good agreement (except for the OH content) with the endmember formula of dravite as known today. [9] Dravite varieties include the deep green chromium dravite and the vanadium ...
Creedite is a calcium aluminium sulfate fluoro hydroxide mineral with formula: Ca 3 Al 2 SO 4 (F,OH) 10 ·2(H 2 O). Creedite forms colorless to white to purple monoclinic prismatic crystals. It often occurs as acicular radiating sprays of fine prisms.