gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1983.047.345.21 Short Communications An Appeal for Reflectance Data on Opaque Minerals for the QDF Cervelle B. Secretary IMA/COM, Laboratoire de Minéralogie Cristallographie, T. 16, 4 Place Jussieu, 75230 Paris Cedex 05, France Criddle A. J. Department of Mineralogy, British Museum (NH), Cromwell Road, London SW7 5BD, England 12 1983 47 345 568 568 22 4 1983 Copyright © 1983, The Mineralogical Society 1983