Four transition metals make up group 11 of the periodic table of elements. All, except one, are considered traditional coinage metals. Qualifying this further, only two of these three traditional coinage metals are considered precious metals. These are gold and silver.
Gold and silver are rare and have high economic values. These things can’t be said of copper, the other traditional coinage metal. Occurring in nature in metallic form, these two precious metals can be produced sans the use of extraction metallurgy. These other characteristics of gold and silver make them both well suited for coinage:
• They are not radioactive.
• They are more ductile or softer than most other elements.
• They are less reactive compared with other elements.
• They have excellent luster.
• They have higher melting points compared with other metals.
The high-ductility property of gold and silver means they can be easily damaged as coins for circulation. Coins intended for circulation must be highly resistant to corrosion and wear. For this reason, gold or silver must be alloyed with other metals (example, manganese) so that the resulting coins will come out harder, more wear-resistant, and not easily damaged or deformed.
As numismatic items, gold and silver coins are made almost entirely of the precious metals, respectively. Current collectible gold coins (the 22-carat gold coins), for example, are made of 92% gold, with silver and copper comprising the rest. 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).
2. 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. 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.
Other notable silver bullion coins include the Australian Silver Kookaburra, Chinese Silver Panda, and the Russian George the Victorious.
Minting coins, whether gold or silver, always entails the risk of having the value of the metal used in the coin greater than the coin’s face value. This is especially true in coins of low denomination. Because of this, there exists the possibility of some smelters taking gold or silver coins and melting these down for the scrap value of the precious metals.
A couple examples, in this regard, are worth mentioning here: US pennies have been made of copper-clad zinc since 1982, when they were before this time made of copper alloys; and British pennies were once made of 97% copper, but are now made of copper-plated steel.
As additional information, gold and silver both have a currency code of ISO 4217.