Kyzylkumite, Ti2V3+O5(OH): new structure type, modularity and revised formula

Armbruster, Thomas Michael; Lazic, B.; Reznitsky, L. Z.; Sklyarov, E. V. (2013). Kyzylkumite, Ti2V3+O5(OH): new structure type, modularity and revised formula. Mineralogical magazine, 77(1), pp. 33-44. Mineralogical Society 10.1180/minmag.2013.077.1.04

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The crystal structure of kyzylkumite, ideally Ti2V3+O5(OH), from the Sludyanka complex in South Baikal, Russia was solved and refined (including the hydrogen atom position) to an agreement index, R1, of 2.34 using X-ray diffraction data collected on a twinned crystal. Kyzylkumite crystallizes in space group P21/c, with a = 8.4787(1), b = 4.5624(1), c = 10.0330(1) Å, β = 93.174(1)°, V = 387.51(1) Å3 and Z = 4. Tivanite, TiV3+O3OH, and kyzylkumite have modular structures based on hexagonal close packing of oxygen, which are made up of rutile TiO2 and montroseite V3+O(OH) slices. In tivanite the rutile:montroseite ratio is 1:1, in kyzylkumite the ratio is 2:1. The montroseite module may be replaced by the isotypic paramontroseite V4+O2 module, which produces a phase with the formula Ti2V4+O6. In the metamorphic rocks of the Sludyanka complex, vanadium can be present as V4+ and V3+ within the same mineral (e.g. in batisivite, schreyerite and berdesinskiite). Kyzylkumite has a flexible composition with respect to the M4+/M3+ ratio. The relationship between kyzylkumite and a closely related Be-bearing kyzylkumite-like mineral with an orthorhombic norbergite-type structure from Byrud mine, Norway is discussed. Both minerals have similar X-ray powder diffraction patterns.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Geological Sciences > Mineralogical Crystallography [discontinued]
08 Faculty of Science > Institute of Geological Sciences

UniBE Contributor:

Armbruster, Thomas Michael

Subjects:

500 Science > 550 Earth sciences & geology

ISSN:

0026-461X

Publisher:

Mineralogical Society

Language:

English

Submitter:

Frank Gfeller

Date Deposited:

27 Apr 2014 16:02

Last Modified:

05 Dec 2022 14:30

Publisher DOI:

10.1180/minmag.2013.077.1.04

BORIS DOI:

10.7892/boris.45429

URI:

https://boris.unibe.ch/id/eprint/45429

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