OREAS 508 was prepared from a blend of porphyry copper-gold ore, barren granodiorite and a minor quantity of Cu-Mo concentrate. The ore was sourced from Northparkes Mine 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-two commercial analytical laboratories participated in the program to certify the elements shown below. The following methods were employed:
- Gold by 15-50g fire assay with AAS (17 laboratories) or ICP-OES (4 laboratories) finish;
- Gold by 10-50g aqua regia digestion with ICP-MS finish (10 laboratories) and AAS (5 laboratories) finish;
- 4-acid digestion for full elemental suite ICP-OES/MS finish (up to 19 laboratories depending on the element)
- Aqua regia digestion for full elemental suite ICP-OES/MS and AAS finish (up to 21 laboratories depending on the element).
Gold by instrumental neutron activation analysis (INAA) on 20 x 85mg subsamples was undertaken to confirm homogeneity (at ANSTO, Lucas Heights, Australia).
| CRM Code |
Principle Certified Values |
State |
Matrix |
Mineralization |
| OREAS 508 |
Au 0.470 ppm |
Cu 0.548% |
Mo 152 ppm |
primary |
granodiorite
|
porphyry copper-gold |