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. A safer estimate would be that they're somewhere between 20K and 23K. Those found in Australia often have higher purity than the ones found in Alaska. It is the third element (after tungsten and carbon) with the highest melting point and the fourth densest (after platinum, iridium, and osmium). Commercially, rhenium is traded in powder form. Its principal application is in the making of certain parts of jet engines. Here, the metal is added to high-temperature nickel-based superalloys. In order of increasing mass abundance (parts per billion), the precious metals are rhenium, rhodium, iridium, ruthenium, osmium, gold, platinum, palladium, and silver. These metals are not radioactive and are mostly used for industrial purposes and for jewelry. Still, precious metals have some safety issues attached to them: Rhenium: Since rhenium is used in very small amounts, its toxicity is virtually unknown. cm-3 Liquid Density (at melting point): 20 g.cm-3 Melting Point: 3033 C, 5491 F, 3306 K Boiling Point: 5012 C, 9054 F, 5285 K Heat of Fusion: 57.85 kJ.mol-1 Heat of Vaporization: 738 kJ.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. A silver certificate allows an investor to buy and sell the security sans the inconveniences associated with the physical silver's transfer. The Perth Mint Certificate Programme, which is fully guaranteed by the Government of Western Australia, is the only silver certificate program in the world that is guaranteed by a national government. Silver: Precious Metal With The Highest Thermal And Electrical Conductivity Silver is generally described as a soft, white, lustrous metallic chemical element. It occurs naturally in its pure form, as an alloy with other metallic elements (especially gold), and in chlorargyrite and other minerals. As one of three coinage metals (the other two being copper and gold), silver is very malleable and ductile.