Chinese Gold Panda (with face values of 500, 200, 100, 50, and 25 Yuan). 3. 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. Minted by the Australian government, this bullion coin is made of 1 kilogram of 99.9% pure gold. Some other bullion coins larger than the Australian Gold Nugget have come out. However, these are not produced in mass quantities and are not practical to handle. Two examples are given here: One is the 100,000-euro Vienna Philharmonic, minted in 2004, which contains 31 kilograms of gold; the other is the 1 million-dollar Canadian Maple Leaf, minted in 2007, which contains 100 kilograms of gold. Compared to gold, platinum is more precious, although its price is considered more volatile. One of the reasons for this is that its demand is driven by industrial uses or applications. For example, its price tends to be double that of gold's when world economy is stable, but significantly goes down in times of economic uncertainty. A few also come in platinum though, including the American Platinum Eagle, the Canadian Platinum Maple Leaf, the Australian Platinum Koala, and the Manx Noble. Here's a quick rundown of each of these four platinum bullion coins: The American Platinum Eagle: The American Platinum Eagle bullion coins were first minted and released in 1997 by the United States Mint. Entering in a Contract For Difference (CFD): Some of the noted financial services firms, especially those in the United Kingdom, provide Contract for Difference (CFD). In this silver investment vehicle, two parties (a "buyer" and a "seller") enter into a contract, in which the seller agrees to pay the buyer the difference between the current value of silver and its value at contract time. Before the turn of the 20th century, countries that were still on silver standard started pegging their monetary units to the gold standard of either the United States or the United Kingdom. For example, Mexico, the Philippines, and Japan pegged their respective silver units to the U.S. dollar at fifty cents.