Jonesite Explained

Jonesite
Category:	Inosilicates
Formula:	Ba4(K,Na)2[Ti<sub>4</sub>Al<sub>2</sub>Si<sub>10</sub>O<sub>36</sub>]•6H2O
Imasymbol:	Jon^[1]
Molweight:	914.93 g/mol
System:	Monoclinic
Class:	Prismatic (2/m) (same H-M symbol)
Symmetry:	P21/m
Unit Cell:	a = 10.618, b = 25.918 c = 8.6945 [Å]; β = 127.633°; Z = 4
Color:	Colorless
Habit:	Bladed– Aggregation is thin blade-like crystals and Tabular– Dimensions thin in one direction
Cleavage:	Distinct
Fracture:	Irregular
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 g/cm^3
Density:	3.25 g/cm^3
Diaphaneity:	Transparent
Other:	Has medium relief and weak dispersion. Has fluorescent luminescence & white streakYear of Discovery:1977
References:	^[2] ^[3] ^[4]

Jonesite is a mineral with the chemical formula Ba₄(K,Na)₂[Ti₄Al₂Si₁₀O₃₆]*6H₂O.^[5] 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.^[6] 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.^[7] In addition to symmetrical properties, Jonesite is a biaxial mineral with birefringence, which is a term to describe the difference between index of refraction.^[8] 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.^[9] 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.^[10] This discovery is important because titanosilicate frameworks have industrial uses in energy companies and are used in containing radioactive waste.^[11]

Notes and References

1. Warr. L.N.. 2021. IMA–CNMNC approved mineral symbols. Mineralogical Magazine. 85. 3. 291–320. 10.1180/mgm.2021.43. 2021MinM...85..291W. 235729616. free.
2. Ralph, J., and Chau I. (2010) Jonesite Mineral Information and Data. Mineralogy Database. Retrieved 23 September 2010, from .
3. Barthelmy, D. (2010) Jonesite Mineral Data. Mineralogy Database. Retrieved 11 September 2010, from .
4. Wise, W., and Pabst, A. (2010) Jonesite. Mineralogical Record. Retrieved 23 September 2010, from .
5. American Geological Institute. (2010) Jonesite. Retrieved 11 September 2010, from
6. Barthelmy, D. (2010) Jonesite Mineral Data. Mineralogy Database. Retrieved 11 September 2010, from .
7. Wise, W., and Pabst, A. (1977) Jonesite: A New Mineral from the Benitoite Gem Mine, San Benito County, California. Mineralogical Record, 8, 453-456.
8. Barthelmy, D. (2010) Jonesite Mineral Data. Mineralogy Database. Retrieved 11 September 2010, from .
9. Wise, W., and Pabst, A. (2010) Jonesite. Mineralogical Record. Retrieved 23 September 2010, from .
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.
11. 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.