Genplesite, Ca (sub 3) Sn(SO (sub 4) ) (sub 2) (OH) (sub 6) .3H (sub 2) O, a new mineral of the fleischerite group; first occurrence of a tin sulfate in nature
Genplesite, Ca (sub 3) Sn(SO (sub 4) ) (sub 2) (OH) (sub 6) .3H (sub 2) O, a new mineral of the fleischerite group; first occurrence of a tin sulfate in nature (in Mineral diversity, complexity and evolution, Sergey V. Krivovichev (editor) and Edward S. Grew (editor))
European Journal of Mineralogy (March 2018) 30 (2): 375-382
- Asia
- cell dimensions
- chemical composition
- Commonwealth of Independent States
- crystal chemistry
- crystal form
- crystal structure
- electron probe data
- formula
- hydrothermal alteration
- infrared spectra
- Krasnoyarsk Russian Federation
- metasomatism
- new minerals
- Norilsk region
- optical properties
- physical properties
- Russian Federation
- Siberia
- spectra
- sulfates
- symmetry
- Taymyr Dolgan-Nenets Russian Federation
- X-ray diffraction data
- Oktyabr'skoye Deposit
- hydrated sulfates
- Oktyabr'sky Mine
- Talnakh Russian Federation
- genplesite
- fleischerite group
The new mineral genplesite, Ca (sub 3) Sn(SO (sub 4) ) (sub 2) (OH) (sub 6) . 3H (sub 2) O, the first natural tin sulfate, is found in cavities in massive chalcopyrite ore at the Oktyabr'skoe Cu-Ni-Pd-Pt deposit (Oktyabr'sky mine), Talnakh, Norilsk district, Siberia, Russia. It is a late-stage hydrothermal mineral associated with greenalite, chamosite, pectolite, ferroactinolite, calcite and fluorapatite. Genplesite occurs as equant, short prismatic or thick tabular hexagonal crystals up to 0.5 mm and crystal clusters up to 0.6 X 1.2 mm. The major crystal forms are {1 0 0} and {0 0 1} whereas {1 0 2} and {1 0 1} are minor. Genplesite is transparent, colourless, with vitreous lustre. It is brittle, the Mohs hardness is ca. 3. Cleavage is not observed, the fracture is conchoidal. D (sub meas) = 2.78(1), D (sub calc) = 2.773 g . cm (super -3) . Genplesite is optically uniaxial (-), omega = 1.597(2), epsilon = 1.572(2). The IR spectrum is reported. The chemical composition (wt%, electron microprobe data, H (sub 2) O calculated for 3 molecules per formula unit, pfu) is: CaO 28.67, Al (sub 2) O (sub 3) 0.11, GeO (sub 2) 0.50, SnO (sub 2) 24.20, SO (sub 3) 27.25, H (sub 2) O (sub calc) 18.34, total 99.07. The empirical formula calculated on the basis of 17 O apfu is: Ca (sub 3.01) (Sn (sub 0.95) Ge (sub 0.03) Al (sub 0.01) ) (sub Sigma 0.99) S (sub 2.01) O (sub 8) (H) (sub 6) . 3H (sub 2) O. Genplesite is hexagonal, P63/mmc, a = 8.5139(2), s = 11.1408(3) Aa, V = 699.37(1) Aa (super 3) and Z = 2. The strongest reflections of the powder X-ray diffraction pattern [d, Aa (I)(hkl)] are: 7.38(68)(1 0 0), 4.259(46)(1 1 0), 3.503(15)(2 0 1), 3.383(1 0 0)(1 1 2), 2.616(13)(2 0 3), 2.493(14)(2 1 2), 2.249(14)(3 0 2) and 2.130(17)(1 0 5, 2 2 0). Genplesite is a member of the fleischerite group. Its crystal structure was solved from single-crystal X-ray diffraction data (R = 0.016). The major building unit of the structure is a column consisting of isolated Sn (super 4+) (OH) (sub 6) octahedra and trimers of edge-sharing CaO (sub 2) (OH) (sub 4) (H (sub 2) O) (sub 2) polyhedra. Adjacent columns are interconnected via H (sub 2) O molecules and SO (sub 4) tetrahedra. Genplesite is named in honour of Gennadiy N. Plesin (b. 1963), a mine surveyor at the Oktyabr'sky mine and an amateur mineralogist who found the mineral.
