A protocol for predicting recovery of platinum group minerals (GRPGM) is adapted from the protocol for gravity recoverable gold. This paper introduces the methodology to characterize the content of GRPGM in samples using the 3-in. (7.5 cm) laboratory Knelson concentrator. Results for two ore samples are presented, as well as some mineralogical analysis of the gravity concentrates. The methodology can also be used for sample preconcentration to aid mineralogical analysis. (C) 2008 Elsevier Ltd. All rights reserved.