When Britain and other countries went off the Gold Standard, they were quite unintentionally initiating a Copper Standard for coins of all values; this has proved to be particularly the case throughout the British Commonwealth.
The golden sovereign was never minted from pure gold, since this would have been too soft for such a purpose. Golden money was standardized in Great Britain at 22-carat, or in other words eleven-twelfths pure; the remainder comprised either silver of copper. Before World War One, silver money was about 99 1/4 percent pure, the rest being copper; but the value of the richer metal increased, so that between the two world wars British silver coins never contained more than 50 percent, a figure which for manufacturing reasons was varied slightly from time to time; the balance was copper. After 1945 the great rise in the price of silver made it necessary even to call in these coins, and in 1947 a cupro-nickel currency was introduced in which the percentages were 75 copper and 25 nickel.
Current 'copper' money contains 95.5 percent copper, 3 percent tin and 1.5 percent zinc. (These and all such figures vary slightly from time to time, depending on the market value of each metal; this always has been the case with monetary currency everywhere.) The threepenny pieces are of brass, viz. copper 79 percent, zinc 20 percent, tin 1 percent.
The total world production of copper coins absorbs thousands of tons of copper every year. The Royal Mint in London alone minted 700 million bronze and cupro-nickel coins in one recent year, representing nearly 7,000 tons of metal.
Coining presses are also used today to make vast numbers of badges, tokens and medals, on a scale which was hitherto unprecedented