OREAS 21f has been prepared from quartz sand to which 0.5% iron oxide has been added to produce a pinkish-tan coloured pulp. This colouring gives the material an appearance of oxide origin (i.e., light orange-brown clay or light iron ore colour). It is characterised by extremely low background gold of less than 1 part per billion.
Ten commercial analytical laboratories participated in the program to characterise the elements reported below. The following methods were employed:
- Au by low level (1ppb reading resolution) fire assay with ICP-OES or ICP-MS finish;
- Full ICP-OES and ICP-MS elemental suites by 4-acid (HF-HNO3-HCl-HClO4) digestion.
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Analyte
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Certified Value
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1SD
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CRM State
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Matrix
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Mineralisation
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Au by fire assay
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0.306
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oxide
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quartz
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barren
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