{{Infobox mineral | name = Fluoborite | category = Borate mineral | boxwidth = | boxbgcolor = | image = Fluoborite.jpg | imagesize = | caption = Fluoborite found in Italy | formula = Mg<sub>3</sub>(BO<sub>3</sub>)(F,OH)<sub>3</sub> | IMAsymbol = Fbo<ref>{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3|pages=291–320|doi=10.1180/mgm.2021.43|bibcode=2021MinM...85..291W|s2cid=235729616|doi-access=free}}</ref> | strunz = 6.AB.50 | system = Hexagonal | class = Dipyramidal (6/m) <br/>H-M symbol: (6/m) | symmetry = ''P''6<sub>3</sub>/m | unit cell = a = 8.8612, c = 3.1021 [Å]; Z = 3 | molweight = 186.61 g/mol | color = Colorless to violet or white | habit = Acicular, prismatic, stellate | twinning = | cleavage = Good on {0001} | fracture = | tenacity = | mohs = 3.5 | luster = Vitreous to silky | refractive = n<sub>ω</sub> = 1.570 n<sub>ε</sub> = 1.534 | opticalprop = Uniaxial (−) | birefringence = 0.036 | pleochroism = | streak = white | gravity = 2.98 | density = | fluorescence = Intense cream-white under SW UV | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = Translucent to transparent | other = | references = <ref name=HBM>[http://rruff.geo.arizona.edu/doclib/hom/fluoborite.pdf Handbook of Mineralogy]</ref><ref name=Mindat>[http://www.mindat.org/min-1566.html Fluoborite on Mindat.org]</ref><ref>[http://webmineral.com/data/Fluoborite.shtml Fluoborite Mineral Data on Webmineral]</ref> }} '''Fluoborite''' has a chemical formula of Mg<sub>3</sub>(BO<sub>3</sub>)(F,OH)<sub>3</sub>. Its name comes from its main chemical components, fluorine and boron. It was first described in 1926.<ref name=Mindat/>
Fluoborite's crystal system is hexagonal, meaning it has one six-fold axis of rotation. It also has a mirror plane perpendicular to the c-axis.<ref>Anthony, J.W., Bideaux, R.A., Bladh, K.W., and Nichols, M.C. (2003)Fluoborite. Handbook of Mineralogy Volume V Borates, Carbonates, Sulfates, 791 p. Mineral Data Publishing, Tucson, AZ.</ref> Fluoborite is uniaxial, just like all other hexagonal minerals. Uniaxial means it has only one optic axis. It is anisotropic. Its relief is low, and it is birefringent.
There are three major settings fluoborite is found. It is found in skarns developed in metamorphosed boron-rich magnesium rocks, contact metamorphosed marble, and in contact metasomatic magnetite deposits. There are two major type localities for fluoborite. One is Tall Mine, Kallmora, Norberg, Västmanland, Sweden. It is an iron mine in a contact metasomatic magnetite deposit. The other type locality is the Huerta del Vinagre mine, Spain.<ref>{{cite journal|last1=Camara|first1=F.|last2=Ottolini|first2=L.|date=2000|title=New data on the crystal-chemistry of fluoborite by means of SREF, SIMS, and EMP analysis|journal=American Mineralogist|volume=85|pages=103-107|url=http://rruff.geo.arizona.edu/doclib/am/vol85/AM85_103.pdf|access-date=2024-05-28}}</ref>
It occurs associated with ludwigite, chondrodite, magnetite and calcite in the Tallgruvan, Sweden occurrence. It occurs with mooreite, willemite, fluorite, hydrozincite, pyrochroite, zincite and rhodochrosite at Sterling Hill, New Jersey.<ref name=HBM/>
== References == {{Reflist}}
Category:Borate minerals Category:Magnesium minerals Category:Hexagonal minerals Category:Minerals in space group 176