Jonesite

Jonesite is a mineral with the chemical formula Ba4(K,Na)2[Ti4Al2Si10O36]*6H2O.[4] 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.[5] 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.[6] In addition to symmetrical properties, Jonesite is a biaxial mineral with birefringence, which is a term to describe the difference between index of refraction.[7] 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.[8] 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.[9] This discovery is important because titanosilicate frameworks have industrial uses in energy companies and are used in containing radioactive waste.[10]

Jonesite
General
CategoryInosilicates
Formula
(repeating unit)		Ba4(K,Na)2[Ti4Al2Si10O36]•6H2O
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupP21/m
Unit cella = 10.618, b = 25.918
c = 8.6945 [Å]; β = 127.633°; Z = 4
Identification
Formula mass914.93 g/mol
ColorColorless
Crystal habitBladed– Aggregation is thin blade-like crystals and Tabular– Dimensions thin in one direction
Cleavage{010} Distinct
FractureIrregular
Mohs scale hardness3–4
LusterVitreous
StreakWhite
DiaphaneityTransparent
Specific gravity3.21 g/cm3
Density3.25 g/cm3
Optical propertiesBiaxial (+), a=1.641, b=1.66, g=1.682, bire=0.0410
Refractive indexIndex: 1.64 to 1.68
Birefringenceδ = 0.041
PleochroismColorless
Other characteristicsHas medium relief and weak dispersion. Has fluorescent luminescence & white streak Year of Discovery:1977
References[1][2][3]

References
  1. 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>.
  2. Barthelmy, D. (2010) Jonesite Mineral Data. Mineralogy Database. Retrieved 11 September 2010, from <http://webmineral.com/data/Jonesite.shtml>.
  3. Wise, W., and Pabst, A. (2010) Jonesite. Mineralogical Record. Retrieved 23 September 2010, from <http://euromin.w3sites.net//mineraux/JONESITE.html>.
  4. American Geological Institute. (2010) Jonesite. Retrieved 11 September 2010, from <http://glossary.agiweb.org/dbtw-wpd/exec/dbtwpub.dll>
  5. Barthelmy, D. (2010) Jonesite Mineral Data. Mineralogy Database. Retrieved 11 September 2010, from <http://webmineral.com/data/Jonesite.shtml>.
  6. Wise, W., and Pabst, A. (1977) Jonesite: A New Mineral from the Benitoite Gem Mine, San Benito County, California. Mineralogical Record, 8, 453-456.
  7. Barthelmy, D. (2010) Jonesite Mineral Data. Mineralogy Database. Retrieved 11 September 2010, from <http://webmineral.com/data/Jonesite.shtml>.
  8. Wise, W., and Pabst, A. (2010) Jonesite. Mineralogical Record. Retrieved 23 September 2010, from <http://euromin.w3sites.net//mineraux/JONESITE.html>.
  9. 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.
  10. 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.
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