Once the base metals are heated at high temperatures, the gold (as well as the other precious metals that may be present) remains apart and the other non-precious metals react forming other compounds. Cupellation basically has two processes: large scale and small scale. Spectrometry: This method is best used to assay platinum bullion or stock. The two coin versions can be distinguished from one another by the number of serrations they have - the proof version has 220, while the bullion has 40 less than the former's. Other nations, such as Canada, Australia, the United States, and the United Kingdom, started producing their own precious metal coins one after the other beginning in 1979. Attached to the inside part of the metal tube are lifter bars. Ore is fed into the trommel through its elevated end. Pressurized water is supplied to the tube and the screen sections. Valuable minerals from the ore are separated by the combination of water and mechanical action. The small pieces of ore bearing the valuable minerals pass through the screen and are concentrated further in sluices. 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. It is the densest natural element, being about 0.03 g/cm3 denser than iridium (the second densest natural element) and about twice as dense as lead. Among the platinum family members, osmium has the highest melting point and the lowest vapor pressure. This precious metal is nearly impossible to fabricate. Following is a list of some of the properties of rhenium: General: Chemical Symbol: Re Atomic Number: 75 Category (as an element): Transition Metal Group/ Period/ Block (in the Periodic Table): 7/ 6/ d Atomic Weight: 186.207 g.mol-1 Electron Configuration: [Xe] 4f14 5d5 6s2 Physical: Density (near room temperature): 21.02 g.