Reference material OREAS 74b is one of a suite of seven nickel sulphide CRMs prepared from high grade massive nickel sulphide ore and barren ultramafic material sourced from Xstrata Nickel's Prospero and Tapinos Nickel mines, located in the Kathleen Valley area approximately 30km north of Leinster in Western Australia within the Agnew-Wiluna portion of the Norseman-Wiluna greenstone belt. It is a typical komatiite-associated, massive sulphide deposit representing an in-situ accumulation of massive and semi-massive primary magmatic Ni-Fe sulphides with minor by-products including Cu, Co and platinum group elements (PGE's).
Nineteen commercial analytical laboratories participated in the program to characterise the elements reported in Tables 1 to 6 (please download certificate). The following methods were employed:
- Lithium borate fusion with X-ray fluorescence (8 laboratories)
- Sodium peroxide fusion or lithium borate fusion with full ICP-OES and ICP-MS suites (14 laboratories)
- Four acid digestion with full ICP-OES and ICP-MS suites (16 laboratories)
- Infra-red combustion furnace for sulphur (14 laboratories)
- Thermogravimetry for Loss On Ignition (9 laboratories)
Due to the presence of reactive sulphides OREAS 74b has been packaged under nitrogen and is available in unit sizes of 10g (single-use laminated foil pouches).
OREAS 74b is a SuperCRM®
| CRM Code |
Principle Certified Values |
State |
Matrix |
Mineralization |
| OREAS 74b |
Ni 3.38% |
Co 490ppm |
As 603ppm |
primary |
mineralized ultramafic |
komatiite-hosted nickel sulphide |