HRTEM observations of structural and chemical modulations in cosalite and its relationship to the lillianite homologues
| dc.contributor.author | Pring, A. | |
| dc.contributor.author | Etschmann, B. | |
| dc.date.issued | 2002 | |
| dc.description.abstract | <jats:title>Abstract</jats:title><jats:p>The results of a HRTEM and electron diffraction investigation of a Cu- and Ag-rich cosalite, Cu<jats:sub>1.2</jats:sub>Ag<jats:sub>0.9</jats:sub>Pb<jats:sub>6.7</jats:sub>Bi<jats:sub>8.2</jats:sub>S<jats:sub>20</jats:sub>, from Ivigtut, Greenland, are presented. Electron diffraction patterns down [001] show pairs of satellite reflections at G<jats:sub>p</jats:sub>±~1/8[140]* and<jats:bold>G</jats:bold><jats:sub>p</jats:sub>±~1/8[<jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" xlink:href="S0026461X00045771_inline1.png"/>40]* in addition to the strong Bragg reflections of the underlying average structure. The superlattice corresponds to a compositional and displacive modulation<jats:bold>G</jats:bold>±<jats:bold>q</jats:bold><jats:sub>prim</jats:sub>where<jats:bold>q</jats:bold><jats:sub>prim</jats:sub>is the primary modulation vector 1/8[140]*. The superlattice is attributed to coupled Ag/Pb/Bi and Cu/□ ordering and associated structural relaxation. The HRTEM images show a complex moire texture due to the structural modulations. Cosalite from Ivigtut, Greenland, also forms coherent intergrowths with members of the lillianite–gustavite series (Pb<jats:sub>3</jats:sub>Bi<jats:sub>2</jats:sub>S<jats:sub>6</jats:sub>–PbAgBi<jats:sub>3</jats:sub>S<jats:sub>6</jats:sub>). A model for the intergrowth between the structures is presented based on sharing both S and Pb atoms in the PbS-like slabs in both structures along [010]<jats:sub>cosalite</jats:sub>.</jats:p> | |
| dc.identifier.citation | Mineralogical Magazine, 2002; 66(3):451-458 | |
| dc.identifier.doi | 10.1180/0026461026630041 | |
| dc.identifier.issn | 0026-461X | |
| dc.identifier.issn | 1471-8022 | |
| dc.identifier.uri | http://hdl.handle.net/2440/13813 | |
| dc.language.iso | en | |
| dc.publisher | Mineralogical Society | |
| dc.source.uri | https://doi.org/10.1180/0026461026630041 | |
| dc.title | HRTEM observations of structural and chemical modulations in cosalite and its relationship to the lillianite homologues | |
| dc.type | Journal article | |
| pubs.publication-status | Published |