Platinum-group metals and their alloys in nuggets from alluvial deposits in Finnish Lapland

Alluvial nuggets of PGE alloys from the rivers Miessijoki, Sotajoki, Puskuoja, Palsinoja and Ivalojoki at Kolmosenkoski rapids and from the Härkäselkä area have been investigated with a microprobe and a scanning electron microscope. PtCu, PdCuAu and OsIrRu alloys occur as well as the main PtFe alloys, both as inclusions in the PtFe alloys and as separate nuggets or crystals. Limited optical properties are given. From the inclusions and associated minerals it is assumed that some of the nuggets are magmatic in origin and that others are a result of oxidative weathering. The material is rounded through transport, although the original euhedral form can often be observed.