Bendadaite, a new iron arsenate mineral of the arthurite group

Autor(en)
Uwe Kolitsch, D. Atencio, N V Chukanov, Natalia V Zubkova, L.A.D. Menezes Filho, J.M.V. Coutinho, William D. Birch, Jochen Schlüter, D. Pohl, Anthony R. Kampf, Ian M. Steele, Georges Favreau, Lutz Nasdala, Steffen Möckel, Gerald Giester, Dmitry Y. Pushcharovsky
Abstrakt

Bendadaite, ideally Fe2+Fe3+2(AsO4)2(OH)2·4H2O, is a new member of the arthurite group. It was found as a weathering product of arsenopyrite on a single hand specimen from the phosphate pegmatite Bendada, central Portugal (type locality). Co-type locality is the granite pegmatite of Lavra do Almerindo (Almerindo mine), Linópolis, Divino das Laranjeiras county, Minas Gerais, Brazil. Further localities are the Veta Negra mine, Copiapó province, Chile; Oumlil-East, Bou Azzer district, Morocco; and Pira Inferida yard, Fenugu Sibiri mine, Gonnosfanadiga, Medio Campidano Province, Sardinia, Italy. Type bendadaite occurs as blackish green to dark brownish tufts ( Y > X, optical dispersion weak, r > v. Optical axis plane is parallel to (010), with X approximately parallel to a and Z nearly parallel to c. Bendadaite has vitreous to sub-adamantine luster, is translucent and non-fluorescent. It is brittle, shows irregular fracture and a good cleavage parallel to {010}. Dmeas. 3.15±0.10 g/cm3, Dcalc. 3.193 g/cm3 (for the empirical formula). The five strongest powder diffraction lines [d in Å (I)(hkl)] are 10.22 (10)(100), 7.036 (8)(110), 4.250 (5)(111), 2.865 (4)(311), 4.833 (3)(020,011). The d spacings are very similar to those of its Zn analogue, ojuelaite. The crystal structure of bendadaite was solved and refined using a crystal from the co-type locality with the composition (Fe2+0.95?0.05)S1.00(Fe3+1.80Al0.20)S2.00(As1.48P0.52)S2.00O8(OH)2·4H2O (R = 1.6%), and confirms an arthurite-type atomic arrangement.

Organisation(en)
Institut für Mineralogie und Kristallographie
Externe Organisation(en)
Russian Academy of Sciences, Lomonosov Moscow State University (MSU), Federal University of Minas Gerais (UFMG), Museums Victoria, Universität Hamburg, Natural History Museum of Los Angeles County, University of Chicago, Naturhistorisches Museum Wien (NHM), Universidade de São Paulo, Independent researcher, Independent researcher
Journal
Mineralogical Magazine
Band
74
Seiten
469-486
Anzahl der Seiten
18
ISSN
0026-461X
DOI
https://doi.org/10.1180/minmag.2010.074.3.469
Publikationsdatum
2010
Peer-reviewed
Ja
ÖFOS 2012
105113 Kristallographie, 104006 Festkörperchemie, 1051 Geologie, Mineralogie
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/def97339-1578-42a3-b93b-9be95dfe2432