On the Occurrence of Niobium-Tantalum and Other Rare-Element Minerals in the Meldon Aplite, Devonshire

Oleg von Knorring and Eric Condliffe
Department of Earth Sciences, The University, Leeds LS2 9JT

Abstract: A number of rare-element minerals from the Meldon aplite are described, e.g. native arsenic and antimony, arsenolite, stibiconite, and various niobiumtantalum minerals. Some of the minerals are new to the occurrence and some may be new to the British Isles. Particular attention has been paid to the Nb-Ta minerals and a large number of electron-microprobe analyses for manganocolumbite, manganotantalite, and microlite are presented. Examination of numerous, minute crystals and fragments of columbite-tantalite revealed a complex oscillatory zoning, indicating a slow rate of cooling and perhaps incomplete miscibility of the isomorphous columbite-tantalite series.

Mineralogical Magazine; September 1984 v. 48; no. 348; p. 443-448; DOI: 10.1180/minmag.1984.048.348.16
© 1984, The Mineralogical Society
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