The Australian Platinum Koala: The Australian Platinum Koala bullion coins were first released in 1988 by the Perth Mint, the oldest currently operating mint in Australia. The coin comes in 1 oz. variety, with a face value of AD100. As with most other bullion coins, this value is much lower than the coin's bullion value. The coins in circulation in the United States prior to 1933 were made of 90% gold and 10% copper-silver combined. Canada's official gold bullion coin - The Canadian Gold Maple Leaf - is made of 99.999% gold; and so are these four other gold bullion coins: 1. British Britannia (with a face value of 100 pounds). 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.mol-1 (first), 1980 kJ.mol-1 (second) The term "gold" was derived from "geolu", an Old English Anglo-Saxon word which means "yellow". Iridium is found at highest concentrations within the Earth's crust in three specific types of geologic structures: in impact craters, in igneous deposits, and in deposits reworked from either of the first two. The Bushveld igneous complex in South Africa is the largest known primary reserves for iridium in the world. Some of the well-known ETFs include iShares Silver Trust (with ticker symbol NYSE: SLV), Central Fund of Canada (with ticker symbols TSX: CEF.NV.A, NYSE: CEF), and ETFS Silver Trust (with ticker symbol NYSE: SIVR). Trading in ETFs means doing away with the inconveniences associated with the handling of physical silver bars. In case the difference is negative, the seller receives payment instead from the buyer. A CFD, therefore, allows an investor to take advantage of long or short positions, enabling him/her to speculate on these markets. In a related scenario, an investor may buy gold early in a condition where there is increased investor confidence.