OREAS 265

OREAS 265 is a low-grade gold certified reference material produced from a
blend of oxide gold ore and a suite of barren volcanic and sedimentary host
rocks sourced from multiple Australian geological terranes.
The blend incorporates oxide gold ore from the Agate Creek district, combined
with barren lithologies including Tuscan Rock, Ettamogah quartz-rich units, and
basaltic scoria. The mineralogical character of the blend reflects weathered
felsic to intermediate volcanics containing dispersed gold ± accessory
sulphides, typical of low-grade oxide gold deposits subjected to lateritic and
supergene processes.
OREAS 265 has been characterized using the following methods:

Gold by Pb collection fire assay (25-50g charge weight) with AAS and
ICP-OES finish
Gold by Bi collection fire assay (30 g charge weight) with AAS finish
Gold by PhotonAssay™
Gold by 15-50g aqua regia digestion with ICP-MS and AAS finish
Gold by cyanide leach (20-200g) with AAS 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
Certified values for applicable analytes are operationally defined for each
method, with results under OREAS ISO 17034 scope of
accreditation.