{{Infobox mineral | name = | boxwidth = | boxbgcolor = | image = Grischunite & Tilasite.jpg | imagesize = 260 | alt = | caption = Grischunite and Tilasite: Well formed orange brown grischunite crystals associated to almost white tilasite crystals. From: Falotta, Tinzen, Grischun, Switzerland | struct image = | struct caption = | struct imagesize = | struct2 image = | struct2 caption = | struct2 imagesize= | SMILES = [Ca+2].[Mg+2].[O-]As(=O)([O-])[O-].[F-] | Jmol = | category = | formula = CaMg(AsO4)F | IMAsymbol = Til<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> | molweight = 222.30 | strunz = 8.BH.10 | dana = 41.5.6.1 | system = Monoclinic | class = | symmetry = | unit cell = a = 6.681 Å, b = 8.950 Å, c = 7.573 Å β = 121.14° | color = | colour = | habit = | twinning = | cleavage = | fracture = | tenacity = | toughness = | mohs = 5 | luster = | streak = | diaphaneity = Translucent | gravity = 3.75 - 3.79 | density = | polish = | opticalprop = Biaxial (-) | refractive = nα = 1.640 nβ = 1.660 nγ = 1.675 | birefringence = 0.035 | pleochroism = | 2V = 83° | dispersion = relatively weak | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | Curie temp = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = | prop1 = | prop1text = | references = | var1 = | var1text = | var2 = | var2text = | var3 = | var3text = | var4 = | var4text = | var5 = | var5text = | var6 = | var6text = }} '''Tilasite''' is an arsenate mineral gemstone, with the elemental formula CaMg(AsO<sub>4</sub>)F. It prefers the monoclinic form of crystal, and has Mohs hardness of 5. It was named in 1895 by Hjalmar Sjögren in honor of Daniel Tilas, who was once director of mines for Sweden, and a regional governor for Västmanland. It was first discovered in Langban, Varmland.<ref>{{cite web | url=https://www.mindat.org/min-3962.html | title=Tilasite }}</ref>
In 1972, Bladh et al. characterised samples found near Bisbee, Arizona.<ref>Bladh K W, Corbett R K, McLean W J, Laughon R B. American Mineralogist 57 (1972) 1880-1884 "The crystal structure of tilasite" http://rruff.geo.arizona.edu/AMS/minerals/Tilasite</ref>
In 1994, Bermanec discovered centro-symmetric Tilasite near Nezhilovo, North Macedonia.<ref>Bermanec V (1994) "Centro-symmetric tilasite from Nezilovo, Macedonia: a crystal structure refinement" Neues Jahrbuch für Mineralogie, Monatshefte 1994 289-294</ref>
==References== {{reflist}}
Category:Fluorine minerals Category:Arsenic minerals Category:Magnesium minerals
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