OREAS 249

OREAS 249 was prepared from a blend of high-grade Au-Sb ore and concentrate from Mandalay Resources’ Costerfield Operation in Victoria, Australia, along with Fosterville ore and barren hornfels.

Gold-antimony mineralisation at Costerfield is hosted in narrow, high-grade quartz-stibnite veins within folded and faulted Lower Silurian metasediments. Mineralisation at Fosterville is similarly orogenic in origin, structurally controlled, and sulphidic in nature. These geological settings make OREAS 249 an ideal matrix-matched reference material for QA/QC applications in high-grade Au-Sb systems.

OREAS 249 has been characterized for gold, majors and traces using the following methods:

• Gold by fire assay with AAS, ICP-OES or ICP-MS finish
• Full ICP-OES and ICP-MS elemental suites by 4-acid (HNO3-HF-HClO4-HCl) digestion
• Full ICP-OES and ICP-MS elemental suites by aqua regia digestion
• Gold by aqua regia digestion
• Antimony by PF ICP-OES/MS
• Antimony by oxidising fusion with XRF finish

Certified values for applicable analytes are operationally defined for each method, with results under OREAS ISO 17034 scope of accreditation.