Mpororoite and Anthoinite from the Kara Mine, Tasmania

Satoshi Matsubara, Akira Kato and Kozo Nagashima
Department of Geology, National Science Museum, 3-23-1 Hyakunin-cho, Shinjuku, Tokyo 160, Japan
Department of Chemistry, The University of Tsukuba, Sakura-mura, Ibaraki 305, Japan

Abstract: The first occurrence of mpororoite and anthoinite outside the African Continent has been found in an altered skarn from the Kara mine, Tasmania, forming a white powdery mixture of the two minerals pseudomorphing scheelite. The wet chemical analysis of the mixture shows WO3, Al2O3, and H2O to be the essential constituents, proving the non-essential nature of Fe2O3 in mpororoite; the original mpororoite contained high Fe2O3 substituting for Al2O3. The thermal treatment of the mixture at 100°C for 6 hours in air brings about the conversion of mpororoite into anthoinite, which re-hydrates into mpororoite, although the associated anthoinite does not. The source of Al is ascribed to the decomposition of aluminian andradite in the skarn.

Mineralogical Magazine; September 1984 v. 48; no. 348; p. 397-400; DOI: 10.1180/minmag.1984.048.348.10
© 1984, The Mineralogical Society
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