OREAS 609d

OREAS 609d was prepared from a blend of gold-copper-silver bearing ores from Evolution Mining’s Mount Carlton Operation in Queensland, Australia and barren rhyodacite rock sourced from a quarry east of Melbourne, Australia. A small amount of copper-gold-silver rich materials sourced from various ores/concentrates was also added to help achieve the desired grades.

The mineralisation assemblage at Mount Carlton consists of pyrite, enargite/tennantite, tetrahedrite, digenite, covellite, sphalerite, galena, alunite, dickite, kaolinite and vuggy silica, hosted in argillic altered rhyodacite containing sulphur-salts.

OREAS 609d has been characterized using the following methods:

• Gold by Pb collection fire assay (25-30 g charge weight) with AAS or ICP-OES finish
• Gold by aqua regia digestion (10-50g sample weight) with AAS or ICP-MS finish
• Full ICP-OES and ICP-MS elemental suites by four-acid (HNO3–HF–HClO4–HCl) digestion
• Full ICP-OES and ICP-MS elemental suites by aqua regia digestion
• Total S by Infrared combustion furnace
• Sulphate S by Na2CO3 leach of sulphates, precipitation as barium sulphate with gravimetric finish (or by difference using the Total S value minus the Sulphide S)
• Sulphide S by Na2CO3 leach of sulphates followed by infrared combustion furnace

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