OREAS 264b
SKU: 264b
OREAS 264b was prepared from a blend of dolomite, black slate and a small
addition of oxide ore. The ore was sourced from the Carlin Trend in Eureka
County, northeastern Nevada. The material was provided by Nevada Gold Mines,
operated under Barrick’s management. The deposit is hosted in carbonate rocks,
where gold occurs as fine-grained, disseminated Carlin-type mineralisation
associated with pyrite and arsenian pyrite in decalcified and weakly silicified
zones. OREAS 264b is sourced from the oxide zone and is low in sulphur but
remains partly refractory due to carbonaceous (organic) matter. Gold occurs as
submicroscopic inclusions within residual sulphides and is also adsorbed onto
organic carbon surfaces, which can exhibit preg-robbing behaviour during
cyanidation.
Fifty-nine commercial analytical laboratories participated in the program to
certify the elements reported below 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™ (protocol PAAU02) with recommended gross fill mass of
520 -550 g
Total C by IR combustion furnace
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
To confirm homogeneity, gold by instrumental neutron activation analysis
(INAA) was undertaken on 20 x 85mg. This format enabled a nested ANOVA treatment
of the INAA results to compare within- and between-unit variances, providing a
statistical measure of batch homogeneity.
Specifications
- State: oxide
- Matrix: siliceous shale
- Mineralisation: Carlin style
- CRM Group: Au, Au only
Certified Values
| Analyte | Certified Value | 1SD | 95% CL Low | 95% CL High | Method |
|---|---|---|---|---|---|
| Au, Gold (ppm) | 0.358 | 0.015 | 0.354 | 0.363 | Pb Fire Assay |
| Au, Gold (ppm) | 0.371 | 0.010 | Bi Fire Assay | ||
| Au, Gold (ppm) | 0.355 | 0.023 | 0.350 | 0.359 | PhotonAssay |
| C, Carbon (wt.%) | 7.10 | 0.170 | 6.97 | 7.23 | Infrared Combustion |
| Ag, Silver (ppm) | 0.203 | 0.017 | 0.180 | 0.227 | 4-Acid Digestion |
| Al, Aluminium (wt.%) | 3.00 | 0.117 | 2.91 | 3.09 | 4-Acid Digestion |
| As, Arsenic (ppm) | 48.0 | 2.24 | 45.5 | 50.5 | 4-Acid Digestion |
| Ba, Barium (ppm) | 835 | 29 | 815 | 856 | 4-Acid Digestion |
| Be, Beryllium (ppm) | 1.06 | 0.092 | 0.97 | 1.14 | 4-Acid Digestion |
| Bi, Bismuth (ppm) | 0.20 | 0.010 | 0.18 | 0.22 | 4-Acid Digestion |
| Ca, Calcium (wt.%) | 10.60 | 0.299 | 10.23 | 10.97 | 4-Acid Digestion |
| Cd, Cadmium (ppm) | 0.18 | 0.02 | 0.15 | 0.20 | 4-Acid Digestion |
| Ce, Cerium (ppm) | 36.3 | 1.87 | 34.8 | 37.8 | 4-Acid Digestion |
| Co, Cobalt (ppm) | 0.84 | 0.13 | 0.74 | 0.94 | 4-Acid Digestion |
| Cr, Chromium (ppm) | 39.6 | 6.0 | 36.0 | 43.2 | 4-Acid Digestion |
| Cs, Caesium (ppm) | 1.96 | 0.075 | 1.87 | 2.05 | 4-Acid Digestion |
| Cu, Copper (ppm) | 21.5 | 1.14 | 20.2 | 22.8 | 4-Acid Digestion |
| Dy, Dysprosium (ppm) | 1.63 | 0.131 | 1.50 | 1.76 | 4-Acid Digestion |
| Er, Erbium (ppm) | 0.84 | 0.049 | 0.78 | 0.90 | 4-Acid Digestion |
| Eu, Europium (ppm) | 0.57 | 0.09 | 0.49 | 0.66 | 4-Acid Digestion |
| Fe, Iron (wt.%) | 1.32 | 0.046 | 1.28 | 1.35 | 4-Acid Digestion |
| Ga, Gallium (ppm) | 8.27 | 0.367 | 7.82 | 8.73 | 4-Acid Digestion |
| Gd, Gadolinium (ppm) | 2.31 | 0.102 | 2.18 | 2.44 | 4-Acid Digestion |
| Hf, Hafnium (ppm) | 1.47 | 0.121 | 1.33 | 1.61 | 4-Acid Digestion |
| Ho, Holmium (ppm) | 0.29 | 0.022 | 0.26 | 0.32 | 4-Acid Digestion |
| In, Indium (ppm) | 0.030 | 0.003 | 0.024 | 0.035 | 4-Acid Digestion |
| K, Potassium (wt.%) | 1.38 | 0.088 | 1.33 | 1.43 | 4-Acid Digestion |
| La, Lanthanum (ppm) | 20.4 | 0.84 | 19.6 | 21.1 | 4-Acid Digestion |
| Li, Lithium (ppm) | 12.6 | 1.4 | 11.8 | 13.4 | 4-Acid Digestion |
| Lu, Lutetium (ppm) | 0.13 | 0.010 | 0.11 | 0.15 | 4-Acid Digestion |
| Mg, Magnesium (wt.%) | 5.95 | 0.162 | 5.80 | 6.09 | 4-Acid Digestion |
| Mn, Manganese (wt.%) | 0.059 | 0.002 | 0.058 | 0.061 | 4-Acid Digestion |
| Mo, Molybdenum (ppm) | 3.97 | 0.206 | 3.74 | 4.19 | 4-Acid Digestion |
| Na, Sodium (wt.%) | 0.062 | 0.010 | 0.057 | 0.066 | 4-Acid Digestion |
| Nb, Niobium (ppm) | 3.17 | 0.85 | 2.72 | 3.63 | 4-Acid Digestion |
| Nd, Neodymium (ppm) | 16.7 | 0.99 | 15.6 | 17.7 | 4-Acid Digestion |
| Ni, Nickel (ppm) | 5.41 | 0.77 | 4.93 | 5.89 | 4-Acid Digestion |
| P, Phosphorus (wt.%) | 0.017 | 0.001 | 0.016 | 0.018 | 4-Acid Digestion |
| Pb, Lead (ppm) | 12.4 | 0.48 | 11.8 | 13.1 | 4-Acid Digestion |
| Pr, Praseodymium (ppm) | 4.57 | 0.253 | 4.28 | 4.87 | 4-Acid Digestion |
| Rb, Rubidium (ppm) | 77 | 4.6 | 74 | 80 | 4-Acid Digestion |
| S, Sulphur (ppm) | 399 | 17 | 381 | 416 | 4-Acid Digestion |
| Sb, Antimony (ppm) | 4.22 | 0.260 | 4.03 | 4.41 | 4-Acid Digestion |
| Sc, Scandium (ppm) | 5.50 | 0.357 | 5.15 | 5.85 | 4-Acid Digestion |
| Sm, Samarium (ppm) | 3.07 | 0.160 | 2.78 | 3.36 | 4-Acid Digestion |
| Sn, Tin (ppm) | 1.68 | 0.130 | 1.58 | 1.79 | 4-Acid Digestion |
| Sr, Strontium (ppm) | 45.0 | 2.03 | 43.7 | 46.4 | 4-Acid Digestion |
| Tb, Terbium (ppm) | 0.32 | 0.023 | 0.29 | 0.35 | 4-Acid Digestion |
| Te, Tellurium (ppm) | < 0.050 | IND | IND | IND | 4-Acid Digestion |
| Th, Thorium (ppm) | 6.99 | 0.413 | 6.57 | 7.42 | 4-Acid Digestion |
| Ti, Titanium (wt.%) | 0.116 | 0.013 | 0.110 | 0.123 | 4-Acid Digestion |
| Tl, Thallium (ppm) | 0.69 | 0.041 | 0.64 | 0.73 | 4-Acid Digestion |
| Tm, Thulium (ppm) | 0.12 | 0.011 | 0.10 | 0.14 | 4-Acid Digestion |
| U, Uranium (ppm) | 2.83 | 0.124 | 2.69 | 2.98 | 4-Acid Digestion |
| V, Vanadium (ppm) | 117 | 6 | 112 | 121 | 4-Acid Digestion |
| W, Tungsten (ppm) | 1.58 | 0.16 | 1.44 | 1.72 | 4-Acid Digestion |
| Y, Yttrium (ppm) | 8.25 | 0.722 | 7.69 | 8.81 | 4-Acid Digestion |
| Yb, Ytterbium (ppm) | 0.82 | 0.054 | 0.74 | 0.90 | 4-Acid Digestion |
| Zn, Zinc (ppm) | 28.5 | 2.42 | 26.9 | 30.1 | 4-Acid Digestion |
| Zr, Zirconium (ppm) | 49.1 | 5.0 | 45.8 | 52.3 | 4-Acid Digestion |
| Ag, Silver (ppm) | 0.102 | 0.014 | 0.087 | 0.116 | Aqua Regia Digestion |
| Al, Aluminium (wt.%) | 0.240 | 0.031 | 0.220 | 0.259 | Aqua Regia Digestion |
| As, Arsenic (ppm) | 47.0 | 2.00 | 44.3 | 49.6 | Aqua Regia Digestion |
| Au, Gold (ppm) | 0.149 | 0.018 | 0.129 | 0.169 | Aqua Regia Digestion |
| B, Boron (ppm) | < 10.0 | IND | IND | IND | Aqua Regia Digestion |
| Ba, Barium (ppm) | 59 | 9 | 52 | 66 | Aqua Regia Digestion |
| Be, Beryllium (ppm) | 0.22 | 0.04 | 0.19 | 0.26 | Aqua Regia Digestion |
| Bi, Bismuth (ppm) | 0.13 | 0.02 | 0.12 | 0.15 | Aqua Regia Digestion |
| Ca, Calcium (wt.%) | 10.62 | 0.637 | 10.23 | 11.02 | Aqua Regia Digestion |
| Cd, Cadmium (ppm) | 0.17 | 0.013 | 0.15 | 0.19 | Aqua Regia Digestion |
| Ce, Cerium (ppm) | 27.4 | 1.88 | 25.8 | 28.9 | Aqua Regia Digestion |
| Co, Cobalt (ppm) | 0.73 | 0.14 | 0.63 | 0.82 | Aqua Regia Digestion |
| Cr, Chromium (ppm) | 12.1 | 1.06 | 11.2 | 13.0 | Aqua Regia Digestion |
| Cs, Caesium (ppm) | 0.47 | 0.05 | 0.43 | 0.52 | Aqua Regia Digestion |
| Cu, Copper (ppm) | 21.2 | 1.37 | 20.1 | 22.4 | Aqua Regia Digestion |
| Fe, Iron (wt.%) | 1.20 | 0.039 | 1.17 | 1.24 | Aqua Regia Digestion |
| Ga, Gallium (ppm) | 0.67 | 0.09 | 0.57 | 0.77 | Aqua Regia Digestion |
| Hf, Hafnium (ppm) | 0.20 | 0.03 | 0.17 | 0.23 | Aqua Regia Digestion |
| Hg, Mercury (ppm) | 0.15 | 0.02 | 0.12 | 0.17 | Aqua Regia Digestion |
| In, Indium (ppm) | 0.010 | 0.001 | 0.009 | 0.012 | Aqua Regia Digestion |
| K, Potassium (wt.%) | 0.167 | 0.022 | 0.154 | 0.180 | Aqua Regia Digestion |
| La, Lanthanum (ppm) | 14.3 | 1.31 | 13.3 | 15.2 | Aqua Regia Digestion |
| Li, Lithium (ppm) | 1.20 | 0.26 | 1.00 | 1.41 | Aqua Regia Digestion |
| Mg, Magnesium (wt.%) | 5.72 | 0.265 | 5.50 | 5.93 | Aqua Regia Digestion |
| Mn, Manganese (wt.%) | 0.058 | 0.003 | 0.056 | 0.060 | Aqua Regia Digestion |
| Mo, Molybdenum (ppm) | 3.85 | 0.320 | 3.62 | 4.08 | Aqua Regia Digestion |
| Na, Sodium (wt.%) | 0.029 | 0.004 | 0.027 | 0.031 | Aqua Regia Digestion |
| Nb, Niobium (ppm) | 0.064 | 0.012 | 0.052 | 0.076 | Aqua Regia Digestion |
| Ni, Nickel (ppm) | 4.16 | 0.60 | 3.75 | 4.58 | Aqua Regia Digestion |
| P, Phosphorus (wt.%) | 0.016 | 0.001 | 0.015 | 0.017 | Aqua Regia Digestion |
| Pb, Lead (ppm) | 8.32 | 1.00 | 7.61 | 9.04 | Aqua Regia Digestion |
| Rb, Rubidium (ppm) | 8.33 | 1.03 | 7.63 | 9.04 | Aqua Regia Digestion |
| S, Sulphur (ppm) | 394 | 15 | 381 | 408 | Aqua Regia Digestion |
| Sb, Antimony (ppm) | 3.00 | 0.39 | 2.76 | 3.23 | Aqua Regia Digestion |
| Sc, Scandium (ppm) | 1.29 | 0.24 | 1.15 | 1.43 | Aqua Regia Digestion |
| Se, Selenium (ppm) | 1.34 | 0.26 | 1.13 | 1.55 | Aqua Regia Digestion |
| Sr, Strontium (ppm) | 31.6 | 2.03 | 30.1 | 33.0 | Aqua Regia Digestion |
| Ta, Tantalum (ppm) | < 0.010 | IND | IND | IND | Aqua Regia Digestion |
| Tb, Terbium (ppm) | 0.22 | 0.021 | 0.19 | 0.26 | Aqua Regia Digestion |
| Th, Thorium (ppm) | 4.52 | 0.50 | 4.15 | 4.89 | Aqua Regia Digestion |
| Ti, Titanium (wt.%) | < 0.005 | IND | IND | IND | Aqua Regia Digestion |
| Tl, Thallium (ppm) | 0.18 | 0.017 | 0.17 | 0.20 | Aqua Regia Digestion |
| U, Uranium (ppm) | 1.58 | 0.135 | 1.48 | 1.69 | Aqua Regia Digestion |
| V, Vanadium (ppm) | 19.9 | 2.2 | 18.6 | 21.1 | Aqua Regia Digestion |
| W, Tungsten (ppm) | 0.31 | 0.04 | 0.27 | 0.36 | Aqua Regia Digestion |
| Y, Yttrium (ppm) | 3.75 | 0.273 | 3.56 | 3.94 | Aqua Regia Digestion |
| Yb, Ytterbium (ppm) | 0.31 | 0.015 | 0.28 | 0.33 | Aqua Regia Digestion |
| Zn, Zinc (ppm) | 24.1 | 1.73 | 22.8 | 25.4 | Aqua Regia Digestion |
| Zr, Zirconium (ppm) | 5.76 | 0.74 | 5.19 | 6.34 | Aqua Regia Digestion |
Product Specifications
Certified Reference Values
| Analyte | Certified Value | Uncertainty (1SD) | 95% Confidence Low | 95% Confidence High | Method |
|---|---|---|---|---|---|
| Ce - Cerium (ppm) | 36.3 | - | - | - | 4-Acid Digestion |
| Dy - Dysprosium (ppm) | 1.63 | - | - | - | 4-Acid Digestion |
| Er - Erbium (ppm) | 0.84 | - | - | - | 4-Acid Digestion |
| Eu - Europium (ppm) | 0.57 | - | - | - | 4-Acid Digestion |
| Gd - Gadolinium (ppm) | 2.31 | - | - | - | 4-Acid Digestion |
| Ho - Holmium (ppm) | 0.29 | - | - | - | 4-Acid Digestion |
| La - Lanthanum (ppm) | 20.4 | - | - | - | 4-Acid Digestion |
| Lu - Lutetium (ppm) | 0.13 | - | - | - | 4-Acid Digestion |
| Nd - Neodymium (ppm) | 16.7 | - | - | - | 4-Acid Digestion |
| Pr - Praseodymium (ppm) | 4.57 | - | - | - | 4-Acid Digestion |
| Sm - Samarium (ppm) | 3.07 | - | - | - | 4-Acid Digestion |
| Tb - Terbium (ppm) | 0.32 | - | - | - | 4-Acid Digestion |
| Tm - Thulium (ppm) | 0.12 | - | - | - | 4-Acid Digestion |
| Y - Yttrium (ppm) | 8.25 | - | - | - | 4-Acid Digestion |
| Yb - Ytterbium (ppm) | 0.82 | - | - | - | 4-Acid Digestion |
| Ag - Silver (ppm) | 0.102 | - | - | - | Aqua Regia |
| As - Arsenic (ppm) | 47.0 | - | - | - | Aqua Regia |
| Bi - Bismuth (ppm) | 0.13 | - | - | - | Aqua Regia |
| Cd - Cadmium (ppm) | 0.17 | - | - | - | Aqua Regia |
| Co - Cobalt (ppm) | 0.73 | - | - | - | Aqua Regia |
| Cu - Copper (ppm) | 21.2 | - | - | - | Aqua Regia |
| Hg - Mercury (ppm) | 0.15 | - | - | - | Aqua Regia |
| Mo - Molybdenum (ppm) | 3.85 | - | - | - | Aqua Regia |
| Sb - Antimony (ppm) | 3.00 | - | - | - | Aqua Regia |
| Se - Selenium (ppm) | 1.34 | - | - | - | Aqua Regia |
| Tl - Thallium (ppm) | 0.18 | - | - | - | Aqua Regia |
SD = Standard Deviation | CL = 95% Confidence Limits
Methods: AR = Aqua Regia, 4-Acid = 4-Acid Digestion, LBF = Lithium Borate Fusion, FA/AAS = Fire Assay with Atomic Absorption, LECO = LECO Combustion Analysis
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