Elemental concentrations of twelve geochemical reference materials of ores and mineralized rocks were determined including
some for which there were few previously published data. Reference materials CHR-Bkg, CHR-Pt, CCU-1c, NBM-1a, NBM-2a, NBM-4a,
NBM-6a, NBM-6b, PM-S, UMT-1, WMG-1, and WMS-1 were analyzed for 34 elements by instrumental neutron activation. To our knowledge,
the analytical results in this paper are among the first published for five reference materials from the Nevada Bureau of
Mines and Geology. Reliable results for Au and Ir down to concentrations of a few ng.g-1were obtained without preconcentration.