Abstract
Experiments with both iron sulphide and copper sulphide precipitates in aqueous solution show that oxygen is significant in determining the mineral phases resulting after heating up to 180 °C. Tetragonal FeS converts to FeS2 and Fe3O4 in the presence of oxygen, while in the absence of oxygen under the same conditions it converts to hexagonal FeS. Suspensions of covellite and of chalcocite under the same conditions convert to digenite in the presence of oxygen, but remain unchanged when oxygen is absent. Experimental evidence is advanced to support structure determinations that CuS contains disulphide ions.
Zusammenfassung
Experimente mit in wässrigen Lösungen ausgefällten Eisen- und Kupfersulfiden dokumentieren die außerordentliche Bedeutung des Sauerstoffes auf die Bildungs- und Verhaltensweise von Mineralphasen, beobachtet nach dem Aufheizen auf 180 °C. So bildet sich aus ursprünglich tetragonalem FeS letzten Endes Pyrit und Magnetit, wenn Sauerstoff zugegen war, während bei dessen Abwesenheit, aber sonst gleichen Versuchsbedingungen, die Umwandlung in hexagonales FeS erfolgte. Suspensionen von Covellin und Chalkosin wurden, unter analogen Versuchsbedingungen und in Gegenwart von Sauerstoff, in Digenit überführt, während sonst, wenn keine Sauerstoffeinwirkung stattfand, die Mineralphasen keinerlei Veränderungen erkennen ließen. Mittels solcher experimenteller Methoden lassen sich bei der Strukturbestimmung des CuS offenbar Merkmale des Vorhandenseins von Disulfidionen erkennen.
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Published by permission of the Director, Bureau of Mineral Resources, Canberra A. C. T., Australia.
Temporary Address: Mineralog.-Petrograph. Inst. Univ. Heidelberg, Berliner Str. 19, 69 Heidelberg, Germany
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Roberts, W.M.B., Buchanan, A.S. The effects of temperature, pressure, and oxygen on copper and iron sulphides synthesised in aqueous solution. Mineral. Deposita 6, 23–33 (1971). https://doi.org/10.1007/BF00207114
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DOI: https://doi.org/10.1007/BF00207114