OREAS 235b

OREAS 235b was prepared from a blend of high-grade, gold-bearing ore and barren metasediments. The ore was sourced from the Fosterville Mine, located 20km from the city of Bendigo in the state of Victoria, Australia. The deposit is hosted by a metamorphosed interbedded turbidite sequence of sandstones, siltstones and shales. Primary gold mineralization occurs as disseminated arsenopyrite and pyrite in a quartz–carbonate veinlet stockwork. Primary gold also occurs as visible gold where it variably overprints sulphide mineralization and is found as disseminated fine specks (>1 mm) of gold within host quartz veins. The visible gold is spatially associated with antimony mineralization, in the form of stibnite that occurs with quartz and varies from replacement and infill of earlier quartz-carbonate stockwork veins, to massive stibnite-only veins of up to 0.5m in width (Hitchman, Philips, & Greenberger, 2017). Thirty-five commercial analytical laboratories participated in the program to certify the elements shown below. The following methods were employed:

  • Gold by fire assay
  • Gold by aqua regia digestion (15-50g sample weight)
  • Gold by cyanide leach
  • Gold by X-ray PhotonAssay
  • 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
  • Instrumental neutron activation analysis of Au on 20 x 85mg subsamples to confirm homogeneity (undertaken at ANSTO)
Analyte Certified Value 1SD Expanded Uncertainty Low Expanded Uncertainty High Method
Au, Gold (ppm) 1.63 0.053 1.61 1.65 Pb Fire Assay
Au, Gold (ppm) 1.60 0.079 1.57 1.64 Aqua Regia Digestion (sample weights 10-50g)
Au, Gold (ppm) 1.43 0.075 1.39 1.47 Cyanide Leach
Au, Gold (ppm) 1.68 0.062 1.65 1.71 PhotonAssay
Ag, Silver (ppm) 0.135 0.028 0.104 0.167 4-Acid Digestion
Al, Aluminium (wt.%) 7.57 0.223 7.38 7.75 4-Acid Digestion
As, Arsenic (ppm) 353 16 340 366 4-Acid Digestion
Ba, Barium (ppm) 691 21 677 706 4-Acid Digestion
Be, Beryllium (ppm) 2.54 0.217 2.36 2.73 4-Acid Digestion
Bi, Bismuth (ppm) 0.34 0.026 0.31 0.38 4-Acid Digestion
Ca, Calcium (wt.%) 0.860 0.038 0.836 0.883 4-Acid Digestion
Ce, Cerium (ppm) 83 3.4 81 86 4-Acid Digestion
Co, Cobalt (ppm) 17.8 0.50 17.0 18.5 4-Acid Digestion
Cr, Chromium (ppm) 128 12 121 136 4-Acid Digestion
Cs, Caesium (ppm) 9.98 0.491 9.60 10.35 4-Acid Digestion
Cu, Copper (ppm) 29.3 1.47 28.3 30.4 4-Acid Digestion
Dy, Dysprosium (ppm) 3.69 0.70 3.14 4.23 4-Acid Digestion
Er, Erbium (ppm) 2.05 0.46 1.71 2.39 4-Acid Digestion
Eu, Europium (ppm) 1.29 0.075 1.20 1.38 4-Acid Digestion
Fe, Iron (wt.%) 4.15 0.124 4.05 4.25 4-Acid Digestion
Ga, Gallium (ppm) 19.9 1.18 18.8 20.9 4-Acid Digestion
Gd, Gadolinium (ppm) 5.23 0.374 4.90 5.55 4-Acid Digestion
Hf, Hafnium (ppm) 3.92 0.347 3.63 4.21 4-Acid Digestion
Ho, Holmium (ppm) 0.71 0.16 0.55 0.87 4-Acid Digestion
In, Indium (ppm) 0.070 0.005 0.061 0.078 4-Acid Digestion
K, Potassium (wt.%) 2.76 0.071 2.69 2.83 4-Acid Digestion
La, Lanthanum (ppm) 40.6 2.14 38.9 42.3 4-Acid Digestion
Li, Lithium (ppm) 55 3.5 53 57 4-Acid Digestion
Lu, Lutetium (ppm) 0.27 0.06 0.21 0.34 4-Acid Digestion
Mg, Magnesium (wt.%) 1.78 0.064 1.74 1.82 4-Acid Digestion
Mn, Manganese (wt.%) 0.041 0.002 0.040 0.042 4-Acid Digestion
Mo, Molybdenum (ppm) 0.98 0.078 0.90 1.07 4-Acid Digestion
Na, Sodium (wt.%) 0.754 0.017 0.735 0.773 4-Acid Digestion
Nb, Niobium (ppm) 15.8 1.31 14.9 16.7 4-Acid Digestion
Nd, Neodymium (ppm) 35.7 1.32 34.4 37.0 4-Acid Digestion
Ni, Nickel (ppm) 66 2.9 64 67 4-Acid Digestion
P, Phosphorus (wt.%) 0.076 0.003 0.074 0.078 4-Acid Digestion
Pb, Lead (ppm) 19.1 1.18 17.9 20.2 4-Acid Digestion
Pr, Praseodymium (ppm) 9.71 0.537 9.27 10.16 4-Acid Digestion
Rb, Rubidium (ppm) 159 11 151 167 4-Acid Digestion
Re, Rhenium (ppm) < 0.002 IND IND IND 4-Acid Digestion
S, Sulphur (wt.%) 0.141 0.008 0.133 0.149 4-Acid Digestion
Sb, Antimony (ppm) 327 16 314 341 4-Acid Digestion
Sc, Scandium (ppm) 14.7 0.94 13.9 15.5 4-Acid Digestion
Sm, Samarium (ppm) 6.80 0.460 6.36 7.24 4-Acid Digestion
Sn, Tin (ppm) 3.79 0.254 3.57 4.01 4-Acid Digestion
Sr, Strontium (ppm) 149 5 146 153 4-Acid Digestion
Ta, Tantalum (ppm) 1.18 0.090 1.11 1.24 4-Acid Digestion
Tb, Terbium (ppm) 0.69 0.048 0.64 0.74 4-Acid Digestion
Th, Thorium (ppm) 14.8 0.68 14.3 15.3 4-Acid Digestion
Ti, Titanium (wt.%) 0.489 0.014 0.476 0.502 4-Acid Digestion
Tl, Thallium (ppm) 0.86 0.037 0.82 0.90 4-Acid Digestion
Tm, Thulium (ppm) 0.30 0.08 0.22 0.37 4-Acid Digestion
U, Uranium (ppm) 2.81 0.159 2.69 2.93 4-Acid Digestion
V, Vanadium (ppm) 111 4 108 114 4-Acid Digestion
W, Tungsten (ppm) 2.34 0.34 2.09 2.60 4-Acid Digestion
Y, Yttrium (ppm) 16.4 2.7 15.0 17.7 4-Acid Digestion
Yb, Ytterbium (ppm) 1.80 0.38 1.54 2.06 4-Acid Digestion
Zn, Zinc (ppm) 97 3.5 94 100 4-Acid Digestion
Zr, Zirconium (ppm) 140 7 134 145 4-Acid Digestion
Ag, Silver (ppm) 0.145 0.011 0.128 0.162 Aqua Regia Digestion
Al, Aluminium (wt.%) 3.02 0.186 2.91 3.14 Aqua Regia Digestion
As, Arsenic (ppm) 352 17 341 364 Aqua Regia Digestion
Ba, Barium (ppm) 96 7.6 91 101 Aqua Regia Digestion
Be, Beryllium (ppm) 1.28 0.16 1.17 1.39 Aqua Regia Digestion
Bi, Bismuth (ppm) 0.34 0.024 0.31 0.36 Aqua Regia Digestion
Ca, Calcium (wt.%) 0.335 0.025 0.320 0.350 Aqua Regia Digestion
Cd, Cadmium (ppm) 0.046 0.015 0.034 0.058 Aqua Regia Digestion
Ce, Cerium (ppm) 56 7 52 61 Aqua Regia Digestion
Co, Cobalt (ppm) 16.9 0.87 16.3 17.5 Aqua Regia Digestion
Cr, Chromium (ppm) 120 5 117 124 Aqua Regia Digestion
Cs, Caesium (ppm) 7.42 0.278 7.11 7.73 Aqua Regia Digestion
Cu, Copper (ppm) 28.4 1.62 27.2 29.6 Aqua Regia Digestion
Fe, Iron (wt.%) 3.67 0.098 3.61 3.74 Aqua Regia Digestion
Ga, Gallium (ppm) 9.46 0.479 9.07 9.84 Aqua Regia Digestion
Ge, Germanium (ppm) 0.12 0.02 0.09 0.15 Aqua Regia Digestion
Hf, Hafnium (ppm) 0.49 0.08 0.43 0.55 Aqua Regia Digestion
In, Indium (ppm) 0.037 0.003 0.035 0.040 Aqua Regia Digestion
K, Potassium (wt.%) 0.900 0.049 0.873 0.927 Aqua Regia Digestion
La, Lanthanum (ppm) 29.1 3.9 26.9 31.3 Aqua Regia Digestion
Li, Lithium (ppm) 45.8 3.08 43.5 48.1 Aqua Regia Digestion
Lu, Lutetium (ppm) 0.13 0.03 0.08 0.18 Aqua Regia Digestion
Mg, Magnesium (wt.%) 1.46 0.075 1.42 1.50 Aqua Regia Digestion
Mn, Manganese (wt.%) 0.031 0.002 0.030 0.032 Aqua Regia Digestion
Mo, Molybdenum (ppm) 0.93 0.060 0.88 0.98 Aqua Regia Digestion
Na, Sodium (wt.%) 0.155 0.013 0.145 0.165 Aqua Regia Digestion
Nb, Niobium (ppm) 0.53 0.15 0.40 0.66 Aqua Regia Digestion
Ni, Nickel (ppm) 61 4.1 59 64 Aqua Regia Digestion
P, Phosphorus (wt.%) 0.068 0.002 0.067 0.069 Aqua Regia Digestion
Pb, Lead (ppm) 9.47 0.686 8.82 10.12 Aqua Regia Digestion
Rb, Rubidium (ppm) 88 3.5 85 91 Aqua Regia Digestion
Re, Rhenium (ppm) < 0.001 IND IND IND Aqua Regia Digestion
S, Sulphur (wt.%) 0.143 0.013 0.134 0.152 Aqua Regia Digestion
Sb, Antimony (ppm) 238 46 216 261 Aqua Regia Digestion
Sc, Scandium (ppm) 7.82 0.647 7.39 8.26 Aqua Regia Digestion
Sn, Tin (ppm) 1.76 0.113 1.65 1.86 Aqua Regia Digestion
Sr, Strontium (ppm) 40.5 2.18 38.2 42.8 Aqua Regia Digestion
Ta, Tantalum (ppm) < 0.010 IND IND IND Aqua Regia Digestion
Th, Thorium (ppm) 12.9 0.54 12.2 13.5 Aqua Regia Digestion
Ti, Titanium (wt.%) 0.193 0.013 0.185 0.201 Aqua Regia Digestion
Tl, Thallium (ppm) 0.53 0.048 0.49 0.57 Aqua Regia Digestion
U, Uranium (ppm) 1.52 0.102 1.44 1.60 Aqua Regia Digestion
V, Vanadium (ppm) 81 3.7 79 83 Aqua Regia Digestion
W, Tungsten (ppm) 0.47 0.06 0.41 0.53 Aqua Regia Digestion
Y, Yttrium (ppm) 9.57 0.741 9.05 10.09 Aqua Regia Digestion
Yb, Ytterbium (ppm) 0.95 0.13 0.78 1.13 Aqua Regia Digestion
Zn, Zinc (ppm) 89 3.2 87 92 Aqua Regia Digestion
Zr, Zirconium (ppm) 20.9 3.7 18.6 23.2 Aqua Regia Digestion
Downloads
Certificate DataPack SDS NRAM (412 KB)
Add to Cart
Stock
  • Pack Size
    Price
    Stock Level
  • 60g Sachet
    $7.20
    71,000 +
  • 500g Jar
    $59.30
    7,800 +
Specifications