gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1977.041.317.22 Columbite from St. Austell, Cornwall Hodkinson I. P. Dept. of Geology, Kingston Polytechnic, Penrhyn Road, Kingston-on-Thames Clark A. M. Dept. of Mineralogy, British Museum (Natural History), Cromwell Road, London SW7 5BD 3 1977 41 317 131 132 20 5 1976 Copyright © 1977, The Mineralogical Society 1977