mol-1 Atomic: Oxidation States: -3, -1, 0, 1, 2, 3, 4, 5, 6 Electronegativity: 2.20 (Pauling scale) Atomic Radius: 136 picometre Covalent Radius: 141 6 picometre Because of its characteristic of being very brittle, pure iridium is quite difficult - almost impossible, in fact - to machine. Its primary use is as a hardening agent for platinum. The Hand of Faith weighs 874.82 troy ounces (60 pounds) and measures 1.54 feet (0.47 meter) x 0.66 feet (0.20 meter) x 0.30 feet (0.09 meter). The Golden Nugget Casino in Las Vegas, Nevada currently houses the nugget. Its sale price was reportedly around 1 million U.S. dollars. Gold nuggets actually are not composed of pure 24K gold. mol-1 Atomic: Oxidation States: 8, 7, 6, 5, 4, 3, 2, 1, 0, -1, -2 Electronegativity: 2.2 (Pauling scale) Atomic Radius: 135 picometre Covalent Radius: 144 4 picometre Ionization Energies: 840 kJ.mol-1 (first), 1600 kJ.mol-1 (second) The name "osmium" was derived from the Greek word "osme", which means "smell". cm-3 Liquid Density (at melting point): 17.31 g.cm-3 Melting Point: 1064.18 C, 1947.52 F, 1337.33 K Boiling Point: 2856 C, 5173 F, 3129 K Heat of Fusion: 12.55 kJ.mol-1 Heat of Vaporization: 324 kJ.mol-1 Atomic: Oxidation States: -1, 1, 2, 3, 4, 5 Electronegativity: 2.54 (Pauling scale) Atomic Radius: 144 picometre Covalent Radius: 136 6 picometre Van der Waals Radius: 166 picometre Ionization Energies: 890.1 kJ. cm-3 Liquid Density (at melting point): 10.38 g.cm-3 Melting Point: 1554.9 C, 2830.82 F, 1828.05 K Boiling Point: 2963 C, 5365 F, 3236 K Heat of Fusion: 16.74 kJ.mol-1 Heat of Vaporization: 362 kJ.mol-1 Atomic: Oxidation States: 0, +1, +2, +4, +6 Electronegativity: 2.2 (Pauling scale) Atomic Radius: 137 picometre Covalent Radius: 139 6 picometre Van der Waals Radius: 163 picometre Ionization Energies: 804.4 kJ. Again, the X-ray fluorescence (XRF) method is the modern assay method widely used today for analyzing precious metals, including (besides silver, gold, and platinum) rhenium, ruthenium, iridium, and palladium. As a non-destructive assay method, XRF can identify various elements in a substance (in fact, even in powder and liquid ones) within a few minutes.