OREAS 153a

OREAS 153a is one of three porphyry Cu-Au-Mo-S certified reference materials prepared from copper ore from the Waisoi district, Viti Levu, Fiji. The two deposits in the area are the Waisoi East deposit (quartz porphyry) and the Waisoi West deposit (diorite porphyry). Copper mineralisation in the region is accompanied by stockwork quartz veinlets and is characterised by bornite-chalcopyrite-pyrite assemblages. Twenty-one analytical laboratories participated in the program to certify the following elements:

  • Gold by fire assay (25-50g charge weight) with AAS (11 laboratories), ICP-OES (9 laboratories) finish and ICP-MS (1 laboratory);
  • Copper, molybdenum and sulphur by 4-acid (HNO3-HF-HClO4-HCl) digestion followed by ICP-OES and/or ICP-MS finish.
Analyte Certified Value 1SD 95% Confidence Limits Low 95% Confidence Limits High Method
Cu, Copper (wt.%) 0.712 0.025 0.701 0.723 4-Acid Digestion
Au, Gold (ppb) 311 12.0 306 315 Pb Fire Assay
Mo, Molybdenum (ppm) 177 9 173 181 4-Acid Digestion
S, Sulphur (wt.%) 1.27 0.070 1.23 1.30 4-Acid Digestion
Certificate DataPack SDS NRAM (231 KB)

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Information is provided for reference only.