OREAS 501d was prepared from a blend of porphyry copper-gold ores, barren granodiorite and a minor quantity of Cu-Mo concentrate. The ores were sourced from both the Ridgeway Mine and Northparkes Mine. Both mines are located in the Central West of New South Wales, Australia. The barren granodiorite was sourced from the mafic, S-Type, Late Devonian Bulla Granodiorite complex located in northern Melbourne, Australia. Twenty commercial analytical laboratories participated in the program to certify the elements reported in Table 1. The following methods were employed:
- Gold by instrumental neutron activation analysis (INAA) on 20 x 85mg subsamples to confirm homogeneity (ANSTO, Lucas Heights, Australia);
- Gold via 25-40g fire assay with AAS finish, ICP-OES or ICP-MS finish;
- Gold via 15-50g aqua regia digestion with ICP OES or MS finish and AAS finish;
- Total Sulphur by infrared combustion furnace;
- 4-Acid digestion for full elemental suite ICP-OES/MS finish;
- Aqua regia digestion for full elemental suite ICP-OES/MS and AAS finish.
| CRM Code |
Principle Certified Values |
State |
Matrix |
Mineralization |
| OREAS 501d |
Au 0.232 ppm |
Cu 0.272% |
Mo 95 ppm |
primary |
quartz monzonite |
porphyry copper-gold |