Porphyroblastic Adularia from Shimabala, Zambia

D. I. J. Mallick
Department of Geology, University of Durham

Summary: An unusual occurrence of adularia as a porphyroblastic mineral in an Upper Pre-Cambrian marble from Zambia is described, and optical and chemical data given. The presence of good cleavages oblique to the crystal faces indicates that the latter are hemi-orthodomes and high index pyramids, although the crystals are of simple form.

Mineralogical Magazine; June 1965 v. 35; no. 270; p. 401-407; DOI: 10.1180/minmag.1965.035.270.14
© 1965, The Mineralogical Society
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