On the average (considering the consistent rise in the exchange rate of gold), the value of gold is around USD12 per gram. Here, it is clear that the currency value assigned by the government to a gold bullion coin has no meaning. Below is a list of some of the government-issued gold and silver bullion coins: 1. 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. Krugerrand: Most Well-Known Precious Metal Coin There are thirty-three known bullion coins in the world. Of these, 5 are made of platinum, 1 of palladium, 9 of silver, and 18 of gold. And of all these precious metal coins, the South African gold bullion coin Krugerrand is perhaps the most popular. In 1967, the South African Mint Company introduced the Krugerrand, with the intention of circulating it as currency. Junk silver coins are older coins with a lower percentage of silver. Examples of these are the dime, quarter, and fifty-cent U.S. coins minted in 1964 or earlier. These coins contain 90% silver and are 8/10 troy ounce per 1 USD of face value. Buying silver bullion bars: This is the most traditional way of investing in silver. There are three placer mining methods used to mine placer gold: Gold Panning: This method, which involves the use of a pan, is the oldest and simplest way to extract gold from a placer deposit. In this method, mined ore is placed in a large pan (made either of plastic or metal) and poured with a liberal amount of water; it is then agitated. Platinum: Most Widely Traded Of The Platinum Group Metals In the periodic table of the chemical elements, six metallic elements - all transition metals - are clustered together and lie in the d-block (the d-block in the periodic table refers to groups 8, 9, and 10, periods 5 and 6). These six elements are collectively referred to as the platinum group metals.