gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1976.040.313.06 The Chemistry of Riebeckites of Massachusetts and Rhode Island Lyons Paul C. 1 Boston University, College of Basic Studies, Boston, Massachusetts 02215, U.S.A.

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 3 1976 40 313 473 479 10 1 1975 6 2 1975 Copyright © 1976, The Mineralogical Society 1976 Summary

Four new chemical analyses are reported for riebeckites of the hypersolvus granites of Massachusetts and Rhode Island. Riebeckites of southern New England are enriched in Li+, which appears to substitute for Fe2+, with additional Na+ coming in to compensate for the charge imbalance.