thumbnail

Crystal structure and crystal chemistry of melanovanadite, a natural vanadium bronze.

American Mineralogist

By:
,

Links

  • The Publications Warehouse does not have links to digital versions of this publication at this time

Abstract

The crystal structure of melanovanadite from Minas Ragra, Peru, has been determined in space group P1. The triclinic unit cell (non-standard) has a 6.360(2), b 18.090(9), c 6.276(2) A, alpha 110.18(4)o, beta 101.62(3)o, gamma 82.86(4)o. A subcell with b' = b/2 was found by crystal-structure analysis to contain CaV4O10.5H2O. The subcell has a layer structure in which the vanadate sheet consists of corner-shared tetrahedral VO4 and double square-pyramidal V2O8 groups, similar to that previously found in synthetic CsV2O5. Refinement of the full structure (R = 0.056) showed that the Ca atom, which half-occupies a general position in the subcell, is 90% ordered at one of these sites in the whole unit cell. Bond length-bond strength estimates indicate that the tetrahedra contain V5+, and the square pyramids, V4+.-J.A.Z.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Crystal structure and crystal chemistry of melanovanadite, a natural vanadium bronze.
Series title:
American Mineralogist
Volume
72
Issue:
5-6
Year Published:
1987
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
637
Last page:
644
Number of Pages:
8