Description
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AMIS0614 Au 0.026 g/t U 4 ppm Wits South Africa
Origin of Material
The standard was made using material from the Ventersdorp Conatct Reef of the Witwatersrand Basin.
Approximate Mineral and Chemical Composition
Throughout the Witwatersrand, gold ores occur in sheets or reefs originally deposited horizontally under water. The thickness of the reefs range between a lie of grit to several meters, with an average of 300mm. The sediments were also intersected by dykes and sills of dolomite, diabase and syenite intruding existing faults. The reefs can be in the form of either course conglomerates, rock pebbles and cemented in a silicate matrix. Pebbles usually derived from vein quarts, may also consist of quarzitic, chert jasper and quartz porphyry. The matrix consists of pure silica, but also contains minute flakes of muscovite and pyrophyllite as well as visible pyrite and other sulphides. The gold is usually confined to the matrix and tends to be concentrated along bedding planes (Vermeulen, 2001).
Recommended Concentrations and Limits
(at two Standard Deviations)
Certified Concentrations
Analyte Method 6(µ) 8 ± (2s) Unit
Au 1Pb Collection 0.026 0.011 g/t
U 24A_MICP 4 1 ppm
LOI 3LOI 1.43 0.18 %
S 4Combustion/LECO 0.21 0.01 %
S 4A_MICP 0.21 0.02 %
As 4A_MICP 25 4 ppm
Ba 4A_MICP 295 17 ppm
Be 4A_MICP 0.9 0.4 ppm
Ca 4A_MICP 381 66 ppm
Ce 4A_MICP 43 7 ppm
Co 4A_MICP 13 1 ppm
Cs 4A_MICP 3 0.4 ppm
Cu 4A_MICP 37 6 ppm
Ga 4A_MICP 10 0.4 ppm
Hf 4A_MICP 2 0.2 ppm
La 4A_MICP 22 3 ppm
Mg 4A_MICP 567 114 ppm
Mn 4A_MICP 54 14 ppm
Mo 4A_MICP 2 1 ppm
Na 4A_MICP 0.10 0.005 %
Ni 4A_MICP 45 2 ppm
Pb 4A_MICP 10 2 ppm
Rb 4A_MICP 61 8 ppm
Sc 4A_MICP 4 0.9 ppm
Sn 4A_MICP 1 0.6 ppm
Sr 4A_MICP 24 4 ppm
Th 4A_MICP 5 0.2 ppm
Ti 4A_MICP 887 204 ppm
V 4A_MICP 28 3 ppm
Yb 4A_MICP 0.4 0.04 ppm
Zn 4A_MICP 12 1 ppm
Major Oxides
Certified Concentrations (at two Standard Deviations)
Analyte Method 6(µ) 8 ± (2s) Unit
U3O8 4A_MICP 0.0005 0.0001 %
Al2O3 5XRF 8.87 0.28 %
CaO XRF 0.05 0.01 %
Fe2O3 XRF 0.93 0.04 %
K2O XRF 1.90 0.049 %
SiO2 XRF 86.15 0.58 %
TiO2 XRF 0.22 0.02 %
