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Rondeau, B., Fritsch, E., Peucat, J.-J., Nordrum, F. S. & Groat, L. (2008) Characterization of emeralds from a historical deposit: Byrud (Eidsvoll), Norway. Gems Gemol. 44 108–122.
Added by: Laurent Cournède (2016-03-10 21:58:41) |
| Type de référence: Article Numéro d'identification (ISBN etc.): 0016-626X Clé BibTeX: Rondeau2008 Voir tous les détails bibliographiques  |
Catégories: MIOPS Mots-clés: beryl, canada, fluid inclusions, geochemistry, southeastern yukon Créateurs: Fritsch, Groat, Nordrum, Peucat, Rondeau Collection: Gems Gemol. |
Consultations : 1/567
Indice de consultation : 4% Indice de popularité : 1% |
| Résumé |
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An emerald deposit at Byrud, in southern Norway, yielded significant quantities of crystals and gem rough in the late 19th and early 20th centuries. Complex multiphase inclusions in the emeralds consist of water, gaseous methane, halite, sylvite, calcite, and a sulfide assemblage (pyrrhotite, galena, and sphalerite). This sulfide assemblage makes it easy to distinguish Byrud emeralds from those from other localities with a binocular microscope. The chemical composition of Byrud emeralds is also characteristic: They are colored mostly by vanadium (up to 1 wt.\% V(2)O(3)), and contain low sodium and magnesium (0.1 wt.\% oxide or less). Moreover, the relative amounts of iron, magnesium, chromium, rubidium, and cesium appear to be diagnostic. Infrared absorption spectra show that they contain little water. Emeralds from the Byrud deposit are still occasionally recovered by hobbyist collectors from the mine dumps.
Added by: Laurent Cournède |