Referenza:
▪ Sapozhnikov, A.N., Kaneva, E.V., Cherepanov, D.I., Suvorova, L.F., Levitsky, V.I., Ivanova, L.A., Reznitsky, L.Z. (2011): Vladimirivanovite, Na6Ca2[Al6Si6O24](SO4,S3,S2,Cl)2·Н22O-a new mineral of the sodalite group.
Zapiski RMO,
140, 36-45.
Abstract:
A new mineral of the sodalite group, vladimirivanovite has been found in Tultuy lazurite deposit in southwestern Baikal region (Irkutsk region, Russia). The mineral is closely associated with lazurite, calcite, afhganite, tounkite, phlogopite and marialite. The mineral occurs as rims on lazurite (0.01—3 mm thick) and elongated grains (from 0.2 to 3-4 mm in size, occasionally up to 4 X 12—15 X 20 mm). Rarely it forms veinlets up to 5 mm in calciphyres and marble. Color is dark blue to ink-blue, as a rule, non-uniform and spotty. Brittle, VHN 522—604, mean 575 kg/mm2, Mohs' hardness 5—5.5. Dmeas = 2.48(3) g/cm3 (by flotation in heavy liquids), Dcalc = 2.436 g/cm3. Vladimirivanovite is optically biaxial, 2V= 63 (±1)°, 2Vcalc = 66.2°, Np- 1.502—1.507 (±0.002), Nm= 1.509-1.514 (±0.002), Ng = grain of various samples are evident. Chemical composition (wt %; electron probe, wet chemistry, H20 was determined by DSC-TG analyses): Si02 32.59, Al:03 27.39, CaO 7.66, Na20 17.74, S03 11.3~7, S 1.94, CI 0.12, H20 1.0, total 99.62. Its empiric formula "(based on Si + Al = 12 atoms pfu and with polysulfide portioned according to charge balance): Na6.36Ca1.522(Si6.03Al5.97)tot=12O23.99](SO4)1.58(S3)0.17(S2)0.08Cl0.04•0.62H2O; the idealized formula is Na6Ca2[Al6Si6O24](SO4,S3,S2,Cl)2·H2O. Crystal structure has been solved on a single crystal. Vladimirivanovite is orthorhombic,
Pnaa,
a= 9.066 A,
b = 12.851 A,
с = 38.558 A,
V = 4492 A3,
Z = 6. The strongest reflections of X-ray powder diagrams (
d, A—I[hkl]) are as following: 6.61—5 [015], 6.43—11 [020, 006], 3.71 — 100 [119, 133], 2.623-30 [20.12, 240], 2.273—6 [04.12], 2.141 — 14 [159, 13.15], 1.783-9 [06.12, 04.18], 1.606—6 [080, 00.24]. Vladimirivanovite is named in memory of Russian mineralogist and geochemist Vladimir Gcorgievich Ivanov (1947—2002). Type specimen of mineral is deposited in Mineralogical Museum of Saint-Petersburg State University.
Edited 1 time(s). Last edit at 01/22/2012 02:38PM by Marco E. Ciriotti.
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