Chemical analyses of a sulphide assemblage from Russeholmen, Nordreisa, North Norway, reveal a selenium content of 0.65 wt% in molybdenite, 0.12 wt% in pyrite and 0.10 wt% in chalcopyrite. These are among the highest selenium concentrations reported for these minerals from Norwegian localities.
Selenium to sulphur ratios are calculated, and a distribution factor for selenium between the minerals is established. The molybdenite contains 240 ppm rhenium. The mineralization occurs in a Precambrian amphibolite belonging to the Caledonian Nabar Nappe. Chemical analyses were done by inductively
coupled plasma optical emission spectrometry, X-ray fluorescence spectrometry and electron microprobe - X-ray spectrometry.