Abstract: A method used in conjunction with prospecting or mineral exploration of sedimentary deposits containing a minute amount of an economic mineral is described. The method is applied to a bulk sample of a deposit and generally involves the steps of washing and wet sieving the sample to produce two or more size fractions, drying the size fraction, separating at least one size fraction into at least two specific gravity fractions and, usually, magnetically separating at least one specific gravity fraction for the purpose of obtaining economic mineral concentration in at least one fraction of such sample. For specific environments where unstable sulphide conditions exist, an acid leach step may be included following specific gravity separation either to a specific gravity fraction or to a fraction resulting from magnetic separation after specific gravity separation.