{{Use dmy dates|date=December 2019}} {{Infobox mineral | name = Jonesite | category = Inosilicates | boxwidth = | boxbgcolor = | image = | imagesize = | caption = | formula = Ba<sub>4</sub>(K,Na)<sub>2</sub>[Ti<sub>4</sub>Al<sub>2</sub>Si<sub>10</sub>O<sub>36</sub>]•6H<sub>2</sub>O | IMAsymbol = Jon<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 = 914.93&nbsp;g/mol | system = Monoclinic | class = Prismatic (2/m) <br/><small>(same H-M symbol)</small> | symmetry = ''P2''<sub>1</sub>/m | unit cell = a = 10.618, b = 25.918 <br/>c = 8.6945&nbsp;[Å]; β = 127.633°; Z&nbsp;=&nbsp;4 | color = Colorless | habit = Bladed– Aggregation is thin blade-like crystals and Tabular– Dimensions thin in one direction | twinning = | cleavage = {010} Distinct | fracture = Irregular | tenacity = | mohs = 3–4 | luster = Vitreous | refractive = Index: 1.64 to 1.68 | opticalprop = Biaxial (+), a=1.641, b=1.66, g=1.682, bire=0.0410 | birefringence = δ = 0.041 | pleochroism = Colorless | streak = White | gravity = 3.21&nbsp;g/cm<sup>3</sup> | density = 3.25&nbsp;g/cm<sup>3</sup> | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = Transparent | other = Has medium relief and weak dispersion. Has fluorescent luminescence & white streak Year of Discovery:1977 | references = <ref>Ralph, J., and Chau I. (2010) Jonesite Mineral Information and Data. Mineralogy Database. Retrieved 23 September 2010, from <http://www.mindat.org/min-2112.html>.</ref><ref>Barthelmy, D. (2010) Jonesite Mineral Data. Mineralogy Database. Retrieved 11 September 2010, from <http://webmineral.com/data/Jonesite.shtml>.</ref><ref>Wise, W., and Pabst, A. (2010) Jonesite. Mineralogical Record. Retrieved 23 September 2010, from <http://euromin.w3sites.net//mineraux/JONESITE.html>.</ref> }}

'''Jonesite''' is a mineral with the chemical formula Ba<sub>4</sub>(K,Na)<sub>2</sub>[Ti<sub>4</sub>Al<sub>2</sub>Si<sub>10</sub>O<sub>36</sub>]*6H<sub>2</sub>O.<ref>American Geological Institute. (2010) Jonesite. Retrieved 11 September 2010, from <http://glossary.agiweb.org/dbtw-wpd/exec/dbtwpub.dll></ref> This mineral is named after Francis Tucker Jones (1905–1993), who discovered the mineral while working as a Research Chemical Microscopist at Berkeley in CA.<ref>Barthelmy, D. (2010) Jonesite Mineral Data. Mineralogy Database. Retrieved 11 September 2010, from <http://webmineral.com/data/Jonesite.shtml>.</ref> Jonesite has diffraction symmetry of mmm, which implies an orthorhombic system with all three axes perpendicular to each other and the angles between each axis equal to 90 degrees.<ref>Wise, W., and Pabst, A. (1977) Jonesite: A New Mineral from the Benitoite Gem Mine, San Benito County, California. Mineralogical Record, 8, 453-456.</ref> In addition to symmetrical properties, Jonesite is a biaxial mineral with birefringence, which is a term to describe the difference between index of refraction.<ref>Barthelmy, D. (2010) Jonesite Mineral Data. Mineralogy Database. Retrieved 11 September 2010, from <http://webmineral.com/data/Jonesite.shtml>.</ref> Jonesite is anisotropic, meaning the speed of light changes through the mineral, so the mineral shows color when viewed in crossed polarized light under a microscope. The mineral also has medium relief, which is a measure of how well the mineral stands out when viewed under a microscope in plane polarized light.<ref>Wise, W., and Pabst, A. (2010) Jonesite. Mineralogical Record. Retrieved 23 September 2010, from <http://euromin.w3sites.net//mineraux/JONESITE.html>.</ref> In addition to being one of the rarest minerals in the Benitoite Gem mine located in California, Jonesite also is the first titanosilicate mineral with a porous double-layered crystal structure.<ref>Krivovichev, S., and Armbruster, T. (2004) The Crystal Structure of Jonesite: A First Example of Titanosilicate with Porous Double Layers. American Mineralogist, 89, 314-318.</ref> This discovery is important because titanosilicate frameworks have industrial uses in energy companies and are used in containing radioactive waste.<ref>Krivovichev, S., and Armbruster, T. (2004) The Crystal Structure of Jonesite: A First Example of Titanosilicate with Porous Double Layers. American Mineralogist, 89, 314-318.</ref>

==References== {{Reflist}}

Category:Inosilicates Category:Monoclinic minerals Category:Minerals in space group 11