Fluorapatite

Fluorapatite

Infobox mineral
name = Fluorapatite
category = Phosphate mineral
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formula = Ca5(PO4)3F
molweight =
color = Sea-green, violet, purple, blue, pink, yellow, brown, white, colorless, may be zoned
habit = Massive to prismatic cyrstaliine
system = Hexagonal - dipyramidal
twinning = Contact twins rare
cleavage = Indistinct
fracture = Brittle to conchoidal
tenacity =
mohs = 5
luster = Vitreous, resinous to dull
polish =
refractive = nω = 1.631 - 1.650 nε = 1.633 - 1.646
opticalprop = Uniaxial (-)
birefringence = δ = 0.002
dispersion =
pleochroism =
fluorescence= Fluorescent and phosphorescent.
absorption =
streak = White
gravity = 3.1 to 3.2
density =
melt =
fusibility =
diagnostic =
solubility =
diaphaneity = Transparent to Opaque
other =
references =http://rruff.geo.arizona.edu/doclib/hom/fluorapatite.pdf Mineral Handbook] [http://webmineral.com/data/Fluorapatite.shtml Webmineral] [http://www.mindat.org/min-1572.html Mindat]

Fluorapatite, often with the alternate spelling of fluoroapatite, is a mineral with the formula Ca5(PO4)3F (calcium halophosphate). Fluorapatite is a hard crystalline solid. Although samples can have various color (green, brown, blue, violet, or colorless), the pure mineral is colorless as expected for a material lacking transition metals. It is an important constituent of tooth enamel.Hurlbert and Klein. "Manual of Mineralogy, 19th Edition". 1977. ISBN 0471251771]

Fluorapatite crystallizes in a hexagonal crystal system. It is often combined as a solid solution with hydroxylapatite (Ca5(PO4)3OH) in biological matrices. Chloroapatite (Ca5(PO4)3Cl) is another related structure.

Fluorapatite is the most common phosphate mineral. It occurs widely as an accessory mineral in igneous rocks and in calcium rich metamorphic rocks. It commonly occurs as a detrital or diagenic mineral in sedimentary rocks and is an essential component of phosphorite ore deposits. It occurs as a residual mineral in lateritic soils.

ynthesis

Fluorapatite can be synthesized in a two 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 (CaF2)) to give the mineral. This reaction is integral in the global phosphorus cycle. [Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.]

:3Ca2+ + 2PO43- → Ca3(PO4)2

:3 Ca3(PO4)2 + CaF2 → 2 Ca5(PO4)3F

Fluorapatite can also be used as a precursor for the production of phosphorus. The mineral can be reduced by carbon in the presence of quartz, ultimately generating white phosphorus, P4::Ca5(PO4)3F + 3SiO2 + 5C → 3CaSiO3 + 5CO + P22P2 → P4 after cooling.

References


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Look at other dictionaries:

  • fluorapatite — /floor ap euh tuyt , flawr , flohr /, n. a crystalline mineral, Ca5(PO4)3F, formed from hydroxyapatite in the presence of fluoride, that has a hardening effect on bones and teeth. [1880 85; < G Fluorapatit; see FLUOR , APATITE] * * * ▪ mineral… …   Universalium

  • fluorapatite — fluorapatitas statusas T sritis chemija apibrėžtis Mineralas. formulė Ca₅(PO₄)₃F atitikmenys: angl. fluorapatite rus. фторапатит …   Chemijos terminų aiškinamasis žodynas

  • fluorapatite — noun A calcium halophosphate mineral, in which fluoride replaces the hydroxide of apatite, that is mined as a phosphate ore, and occurs in the enamel of teeth …   Wiktionary

  • fluorapatite — A naturally occurring fluorophosphate of calcium …   Medical dictionary

  • fluorapatite —    A cave mineral Ca5(PO4)3F [11] …   Lexicon of Cave and Karst Terminology

  • fluorapatite — flu·or·apatite …   English syllables

  • fluorapatite — noun a form of apatite in which fluorine predominates over chlorine • Hypernyms: ↑apatite • Substance Meronyms: ↑fluorine, ↑F, ↑atomic number 9 * * * flu̇(ə)ˈr, flōr, flȯˈr+ noun Etymology …   Useful english dictionary

  • carbonate-fluorapatite —    A cave mineral Ca5(PO4,CO3)3F [11] …   Lexicon of Cave and Karst Terminology

  • Apatite — Catégorie VIII : phosphates, arséniates, vanadates[1] Apatite Québec (Xl 32cm) …   Wikipédia en Français

  • Fluorapatit — (ehemals Apatit (CaF)) Doppelender Kristall in Calcit aus Quebec, Kanada Chemische Formel Ca5[F|(PO4)3][1] Mineralklass …   Deutsch Wikipedia

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