Cadmoindite

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Cadmoindite
Cadmoindite.jpg
Cadmoindite, from Kudriavy Volcano, Far Eastern Region, Russian Federation
General
CategorySulfide mineral
Thiospinel group
Spinel structural group
Formula
(repeating unit)
CdIn2S4
Strunz classification2.DA.05
Crystal systemCubic
Crystal classHexoctahedral (m3m)
H-M symbol (4/m 3 2/m)
Space groupFd3m
Unit cella = 10.81 Å; Z = 8
Identification
Formula mass470.32 g/mol
ColorBlack to dark brown
Crystal habitMicroscopic octahedral crystals
FractureConchoidal
LusterAdamantine
Diaphaneitytranslucent
Optical propertiesIsotropic
References[1] [2]

Cadmoindite (CdIn2S4) is a rare cadmium indium sulfide mineral discovered in Siberia around the vent of a high-temperature (450–600 °C) fumarole at the Kudriavy volcano, Iturup Island in the Kuril Islands. It has also been reported from the Kateřina Coal Mine in Bohemia, Czech Republic.[2]

Crystal Structure[edit]

CdIn2S4 exhibits the spinel structure, which can be described by a cubic unit cell with 8 tetrahedrally coordinated and 16 tetrahedrally coordinated cation sites. The distribution of Cd(II) and In(III) over the cation sites is difficult to elucidate from standard X-Ray Diffraction techniques because the two species are isoelectronic, but both Raman spectroscopy measurements on synthetic samples[3] and density functional theory simulations[4] indicate that about 20% of the tetrahedral sites are occupied by In(III) cations.

References[edit]

  1. ^ Cadmoindite Webmineral Data
  2. ^ a b Cadmoindite mineral information from Mindat.org
  3. ^ Ursaki, V. V.; Manjon, F. J.; Tiginyanu, I. M.; Tezlevan, V. E. (2002). "Raman scattering study of pressure-induced phase transitions in MIn2S4 spinels". J. Phys.: Condens. Matter. 14: 6801. doi:10.1088/0953-8984/14/27/304.
  4. ^ Seminovski, Y.; Palacios, P.; Wahnon, P. M.; Grau-Crespo, R. (2012). "Band gap control via tuning of inversion degree in CdIn2S4 spinel". Applied Physics Letters. 100: 102112. arXiv:1202.4752. Bibcode:2012ApPhL.100j2112S. doi:10.1063/1.3692780.