Jonesite
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| Jonesite | |
|---|---|
| General | |
| Category | Inosilicates |
| Formula | Ba4(K,Na)2[Ti4Al2Si10O36]•6H2O |
| IMA symbol | Jon[1] |
| Crystal system | Monoclinic |
| Crystal class | Prismatic (2/m) (same H-M symbol) |
| Space group | P21/m |
| Unit cell | a = 10.618, b = 25.918 c = 8.6945 [Å]; β = 127.633°; Z = 4 |
| Identification | |
| Formula mass | 914.93 g/mol |
| Color | Colorless |
| Crystal habit | Bladed– Aggregation is thin blade-like crystals and Tabular– Dimensions thin in one direction |
| Cleavage | {010} Distinct |
| Fracture | Irregular |
| Mohs scale hardness | 3–4 |
| Luster | Vitreous |
| Streak | White |
| Diaphaneity | Transparent |
| Specific gravity | 3.21 g/cm3 |
| Density | 3.25 g/cm3 |
| Optical properties | Biaxial (+), a=1.641, b=1.66, g=1.682, bire=0.0410 |
| Refractive index | Index: 1.64 to 1.68 |
| Birefringence | δ = 0.041 |
| Pleochroism | Colorless |
| Other characteristics | Has medium relief and weak dispersion. Has fluorescent luminescence & white streak Year 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]