{{Infobox mineral | name = Billwiseite | category = Oxide minerals | image = | imagesize = | caption = | formula = (Sb<sup>3+</sup>)<sub>5</sub>(Nb,Ta)<sub>3</sub>WO<sub>18</sub> | IMAsymbol=Bwi<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 = 4.DX | system = Monoclinic | class = Prismatic (2/m) <br/><small>(same H-M symbol)</small> | symmetry = ''C2/c'' | unit cell = a = 54.206(6)&nbsp;Å, <br/>b = 4.9163(5)&nbsp;Å, <br/>c = 5.5540(6)&nbsp;Å; <br/>β = 90.396(2)°; Z&nbsp;=&nbsp;4 | color = Pale yellow (with a tinge of green) | habit = | twinning = | cleavage = {100} Indistinct | fracture = Hackly | mohs = 5 | luster = Vitreous | refractive = unknown | opticalprop = | birefringence = | pleochroism = | streak = Colorless, very pale yellow | gravity = 6.33 | density = | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = | other = | references = <ref>[https://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Billwiseite Mineralienatlas]</ref><ref name=Mindat>[http://www.mindat.org/min-43328.html Billwiseite on Mindat.org]</ref><ref name="HawthorneCooper2012">{{cite journal|last1=Hawthorne|first1=F. C.|last2=Cooper|first2=M. A.|last3=Ball|first3=N. A.|last4=Abdu|first4=Y. A.|last5=Cerny|first5=P.|last6=Camara|first6=F.|last7=Laurs|first7=B. M.|title=Billwiseite, Ideally Sb3+5(Nb,Ta)3WO18, A New Oxide Mineral Species from the Stak Nala Pegmatite, Nanga Parbat - Haramosh Massif, Pakistan: Description and Crystal Structure|journal=The Canadian Mineralogist|volume=50|issue=4|year=2012|pages=805–814|issn=0008-4476|doi=10.3749/canmin.50.4.805|bibcode=2012CaMin..50..805H }}</ref> }}

'''Billwiseite''' is a very rare oxide mineral found at the pegmatite commonly referred to as "Stak Nala" located within a few hundred yards from the village of Toghla in the Stak Nala, Gilgit-Baltistan, Pakistan. It has only been found as a coating on a single crystal of lepidolite. The sole rock containing Billwiseite is kept at the Royal Ontario Museum, catalogue number M5595.<ref name=Mindat/><ref name="HawthorneCooper2012"/>

It contains four relatively uncommon elements: antimony, niobium, tantalum, and tungsten. It is named after William Wise, a mineralogist from the University of California, Santa Barbara.<ref name="HawthorneCooper2012"/>

It was discovered by an international group of geologists, and accepted by the IMA in 2010. Its discovery was announced in ''Mineralogical Magazine'' in 2011, and was described in detail in 2012 in ''The Canadian Mineralogist'' by Hawthrone et al.<ref name="HawthorneCooper2012"/>

==References== {{reflist}}

Category:Oxide minerals Category:Antimony minerals Category:Niobium minerals Category:Tantalum minerals Category:Tungsten minerals Category:Monoclinic minerals Category:Minerals in space group 15 Category:Minerals described in 2012