RE-EXAMINATION OF YUSHKINITE: CHEMICAL COMPOSITION, OPTICAL PROPERTIES AND INTERLAYER CHARGE TRANSFER

Show simple item record

dc.contributor.author Moëlo Y.
dc.contributor.author Cario L.
dc.contributor.author Rouer O.
dc.contributor.author Cervelle B.
dc.date.accessioned 2021-01-12T11:16:06Z
dc.date.available 2021-01-12T11:16:06Z
dc.date.issued 1999
dc.identifier https://elibrary.ru/item.asp?id=13769214
dc.identifier.citation Mineralogical Magazine, 1999, , 6, 879-889
dc.identifier.issn 0026-461X
dc.identifier.uri https://repository.geologyscience.ru/handle/123456789/22789
dc.description.abstract The hydroxy-sulphide yushkinite from the type deposit has been re-examined by electron probe microanalysis and reflectance measurement. The EPMA indicates minor Cu (up to 1.5 wt.%) and confirms an excess of V. Taking into account its composite structure (brucite-like hydroxide layer alternating with a berndtite-type sulphide layer) the proposed structural formula is, with the addition of minor intercalated Cu: [(Mg0.71Al0.36V0.03) Σ1.10(OH)2.18O0.02]Cu0.02 [VS2]. At the crystal scale, some crystal edges give a variable excess of Si and Al (in the 1/1 ratio), indicating a late topotactic intergrowth with a layered alumino-silicate (or a composite silicate-sulphide). New specular reflectance data are given in air and oil from 400 to 800 nm, with the polarization plane parallel or perpendicular to the elongation. The refractive index n and absorption coefficient k are given; no absorption band exists in the perpendicular position, with constant n close to 1.9, and k to 0.3. In a parallel position, a pseudo-transparency window is centred around 500-520 nm (~2.4 eV). The main absorption band, centred around 730 nm (~1.7 eV), corresponds probably to a transition t2g→ eg related to intra-layer V-V bonding. Charge transfer from the brucite-type layer to the VS2 one, strictly controlled through H-bonding, induces a mean formal valency of V close to 3.6. Yushkinite is compared with other synthetic layered hydroxy-sulphides, as well as brucite-type intercalated compounds.
dc.title RE-EXAMINATION OF YUSHKINITE: CHEMICAL COMPOSITION, OPTICAL PROPERTIES AND INTERLAYER CHARGE TRANSFER
dc.type Статья


Files in this item

Files Size Format View

There are no files associated with this item.

This item appears in the following Collection(s)

  • ELibrary
    Метаданные публикаций с сайта https://www.elibrary.ru

Show simple item record