Quarter ounce coin (0.27 troy ounce in weight, 1.89 millimeters thick, and 22.06 millimeters in diameter). 3. Half ounce coin (0.55 troy ounce in weight, 2.22 millimeters thick, and 27.07 millimeters in diameter). 4. One ounce coin (1.09 troy ounces in weight, 2.84 millimeters thick, and 32.77 millimeters in diameter). The Hand of Faith Gold Nugget: This gold nugget actually carries two distinctions: "the largest gold nugget found by a metal detector" and "the largest gold nugget currently in existence". It was discovered on September 26, 1980 somewhere near the small town of Kingower in Victoria, Australia. Some of the properties osmium possesses are outlined below. General: Chemical Symbol: Os Atomic Number: 76 Category (as an element): Transition Metal Group/ Period/ Block (in the Periodic Table): 8/ 6/ d Atomic Weight: 190.23 g.mol-1 Electron Configuration: [Xe] 4f14 5d6 6s2 Physical: Density (near room temperature): 22.59 g. In earlier times, precious metals were mainly used as currency. Today, however, they are highly regarded as investment and industrial commodities. Four of them, in fact - silver, gold, platinum, and palladium -, are minted into coins or cast into ingots and traded on commodity markets. All four are assigned the ISO 4217 currency code. Compared with silver or gold, platinum tends to trade at a higher per-unit price because it is scarcer and has lower mine output. The average mine production of platinum is 5 million troy ounces per year. This is lower by about 77 million troy ounces when compared with the annual mine production of gold, and even much lower - by about 547 million troy ounces - when compared with the yearly silver mine production. Significant amounts of mineable palladium are also found in two other places: the Lac des les igneous complex in northwestern Ontario, Canada and the Stillwater igneous complex in the state of Montana in the United States. Such is the rarity and preciousness of palladium that many metric tons of ore have to be processed to obtain just a troy ounce of the precious metal.