OREAS 320

OREAS 320 is a certified reference material produced from a blend of
zinc-lead-silver ores and concentrates sourced from several Australian mining
operations. Key contributors include Zn-Pb-Ag ores from the George Fisher Mine
at Mount Isa (Glencore), Mt Isa and Dugald River zinc concentrates, and a
high-grade lead concentrate from the Rosebery Mine in Tasmania. These materials
represent diverse mineralisation styles, including SEDEX-type deposits hosted
within carbonaceous dolomitic sediments of the Urquhart Shale Formation in NW
Queensland and volcanogenic massive sulphide (VMS) mineralisation at Rosebery. A
minor proportion of barren black slate was included to assist in balancing
matrix composition, and a specially prepared silver-rich blend—produced by
combining silver granules with rhyodacite, granite, and quartz sand—was used to
elevate the silver content.
OREAS 320 has been characterized using the following methods:

Major elements by borate/ oxidising fusion with XRF finish
LOI at 1000 °C using a muffle furnace or thermogravimetric analyser (TGA)
Full ICP-OES and MS elemental suites by peroxide fusion
Full ICP-OES and MS elemental suites by 4-acid (HCl-HNO3-HF-HClO4)
digestion
Full ICP-OES and MS elemental suites by aqua regia digestion
Total C and Total S by infrared combustion furnace
Certified values for applicable analytes are operationally defined for each
method, with results under OREAS ISO 17034 scope of
accreditation.