Mexican Centenario, Libertad, and Onza 6. Polish Orzel bielik 7. South African Krugerrand 8. Swiss Vreneli 9. British Britannia and Sovereign 10. American Buffalo, American Eagle, and Double Eagle The 10,000-dollar Australian Gold Nugget is one of the world's largest bullion coins. Minted by the Australian government, this bullion coin is made of 1 kilogram of 99.9% pure gold. Its symbol "Au", on the other hand, originated from "aurum", the Latin word for "gold". The exact period when gold was first discovered could be a subject of dispute. While some accounts point to the year 1848 when gold was discovered in California, history tells us that this precious metal was already being used extensively by the ancient Egyptians, Romans, Greeks, Chinese, and South Americans. Swiss Helvetia Head (with face values of 100, 20, and 10 Swiss francs). 4. Austrian Vienna Philharmonic (with face values of 100, 50, 25, and 10 euros). Silver coins, like the minted coins circulated in the United States and other countries prior to 1965, were made of 90% silver and 10% copper. The American Silver Eagle and the Mexican Silver Libertad bullion coins, introduced in 1986 and 1982 respectively, were made of 99.9% silver and 0.1% copper. 1/10 ounce (oz.) coin - With a face value of USD10, 3.112 grams (g) in weight, 0.95 millimeters (mm) thick, and 16.5 mm in diameter. 2. 1/4 oz. coin - With a face value of USD25, 7.78 g in weight, 1.32 mm thick, and 22 mm in diameter. 3. 1/2 oz. coin - With a face value of USD50, 15.56 g in weight, 1.75 mm thick, and 27 mm in diameter. 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". General: Chemical Symbol: Rh Atomic Number: 45 Category (as an element): Transition Metal Group/ Period/ Block (in the Periodic Table): 9/ 5/ d Atomic Weight: 102.90550 g.mol-1 Electron Configuration: [Kr] 4d8 5s1 Physical: Density (near room temperature): 12.41 g.cm-3 Liquid Density (at melting point): 10.7 g.