OREAS 172 is a supergene manganese ore matrix-matched certified reference material (MMCRM) prepared and certified by Ore Research & Exploration Pty Ltd. The material was sourced from the Groote Eylandt Mining Company Pty Ltd (GEMCO) Mn deposit which is hosted within a shallow dipping Lower Cretaceous sedimentary rock unit. Groote Eylandt is in the Gulf of Carpentaria off the coast of Australia's Northern Territory. A portion (22%) of barren siltstone sourced from a quarry north of Melbourne, Australia was added to lower the grade. OREAS 171 is one of a suite of four Mn ore MMCRMs certified by borate fusion XRF covering a Mn grade range of 35-46%.
| CRM Code |
Principle Certified Values |
State |
Matrix |
Mineralization |
| OREAS 172 |
Mn 42.75% |
SiO2 14.09% |
Fe 3.83% |
oxide |
manganiferous sedimentary |
shallow marine sediment hosted |