The Poor-Relative Coinage Metal

Aluminum – The Poor-Relative Coinage Metal.

By: MICC Lifetime member #001

When it comes to being a coinage metal, we tend to think of aluminum as one of the “junk” metals, ranking just ahead of zinc. Everything conspires to make this so: it is used only by second- and third-world countries; it is used for only the lowest denominations; its light weight gives a feeling of being insubstantial; it wears to a dull, ugly gray and is usually full of nicks and scratches. Undesirable, when everything is factored in.

But it wasn’t always that way. During the early Nineteenth Century, it was a “precious metal” and held in high regard. As a metal all on its own, aluminum only dates from about 1827 when Friedrich Wöhler is credited with isolating it; in the form of alum, an aluminum salt, it was known to the ancient Greeks who used it in the dyeing process.

Aluminum was rare only because it does not naturally exist in a pure state, its great affinity to oxygen ensuring that it is normally a hydrate (some of which are surprising: corundum, ruby, topaz and sapphire), “bauxite” being the commercial ore normally exploited. In the earth’s crust, aluminum is scarcer than only oxygen and silicon, forming roughly 1/13th part of it.

Wöhler succeeded in producing metallic aluminum in the form of a gray powder and later as pellets by chemical means: the displacement of aluminum from its chloride by means of potassium. Over the next 25 years, the process was rendered cheaper by the substitution of cryolite (double aluminum flouride) for aluminum chloride and sodium for potassium. All the same, the price for aluminum remained high, the new process merely dropping it from $600 to $250 per kilogram! It remained for two inventors, working independently, to come up with the process largely used today. Charles M. Hall of the United States and Paul L. T. Héroult of France – almost simultaneously in 1886 – came up with the process by which aluminum oxide, dissolved in molten cryolite, was separated from the other elements by electrolysis. Fortunately, the cryolite is mostly recovered, making the process semi-continuous but the large electric currents burn away the carbon anodes. In the 1920s, it was calculated that a ton of aluminum was refined by the use of 1.88 tons of bauxite ore, about 1/2-ton of carbon, .1 ton cryolite and the equivalent of 3 2/3-horsepower of electricity. For this reason, aluminum production has gravitated to places where hydroelectric power was cheapest, the biggest exporters in the 1920s being Norway, Switzerland and Canada (in that order); the largest producer and user of aluminum by far was the U.S. who produced about 40% of the world’s supply in 1926 and still had to import 40% more than that.

Emperor Louis Napoleon III of France (1852-1870) was much taken with aluminum and early on had aluminum plate made of this then-expensive metal on which most-favoured guests might dine at banquets. Rarely the brightest candle on the altar, he also conceived the idea of replacing all iron and steel implements in the armed forces with aluminum, thus making it more mobile. Technical and financial difficulties he airily dismissed; what won over the slightly xenophobic Louis was the fact that France would have to depend on foreign countries for both the raw aluminum ore as well as the catalytic cryolite – so the idea was scrapped.

Nigeria-British West Africa,
1/10 Penny, 1907-8

East Africa & Uganda,
1 Cent, 1907-8 (1/2-cents also in 1908)

It was not until the Twentieth Century that circulating aluminum coins started to appear, even though it was a favorite metal on which to strike coin patterns for decades. By 1907, the price of aluminum had been brought very low and British authorities felt it was a good metal to use for minor coins in their tropical African possessions since it did not corrode, an important consideration in a hot, humid climate where the effects of human perspiration ruined most coins quickly. Therefore aluminum 1/10-pennies were struck for British West Africa in 1907 and 1908 while East Africa – Uganda saw aluminum cents in 1907 and both cents and half-cents in 1908. They were not a success and became copper-nickel or pure nickel coins in following years.

GERMANY, Al. 1-pfennig, 1916-18;

REUNION, Al. 25-Centimes, 1920

At the outbreak of the First World War in August, 1914, gold coinage at once disappeared from the circulation of the combatant countries, followed almost immediately by the silver in most. Fought with paper money, the fiction was maintained that the various currencies had kept their old, gold values. That was true in very few cases but in the meantime coinage tended to cease using metals needed by the military – such as copper and nickel – and be replaced by much cheaper zinc, iron and (yes) aluminum. For official circulation, Germany was the first to strike these substitute aluminum coins for the lowly 1-pfennig in 1916, although in much fewer numbers than they would be in 1917 and ’18. Unofficially, aluminum saw extensive use in the private token coinages of numerous private persons, companies, credit leagues and municipalities. Although official, the above aluminum 25-centime coin from the French possession of Reunion in 1920 was a typical example of these private tokens.

If aluminum saw extensive unofficial use during the war, it became much more officially common in the first days of the peace. Most nations scrambled to stabilize their currencies at a value as close to the old pre-War value as possible, but few succeeded. Practically all had devaluations to some extent in terms of gold, that of Germany being one of the worst. The old mark, worth some 21-cents U.S. before the War, sank and kept sinking until, in 1923, it was revalued at an unbelievable 1 billion old marks equal to just 1 new “Retenmark”, the retenmark now worth 21-cents U.S. By 1921, German inflation had set in severely enough that the formerly silver 50-pfennig piece was now aluminum and by 1923, there were even aluminum 500-mark pieces. Although to a much lesser extent, other countries had to devalue as well, the Greek aluminum 10-lepta piece shown above had been nickel just ten years previously. At about the same time, Bulgaria issued 1- and 2-leva pieces in aluminum, coins that had been silver as recently as 1916.

Germany, Al. 50-pfennig, 1921

Greece, Al. 10-lepta, 1922

Aluminum didn’t always appear to be aluminum since a favorite alloy from the 1920s onward was “aluminum-bronze”, actually an amalgam of copper and aluminum. When new, it resembles freshly minted gold but soon tarnished to a “brassy” look. Much like our tombac 5-cent pieces issued during WWII.

The war caused a lot of aluminum coins to appear (as well as zinc, iron and other “junk” metals). France coined aluminum 50-centimes, 1- and 2-franc pieces from 1941 onward while the German 50-pfennig , previously in nickel, became aluminum as well 1939-44. The Japanese 1-sen, a half-penny-size bronze coin until 1938, abruptly became a dime-size aluminum coin 1938-43, then a tin piece (1944-5) then dropped altogether; the larger 5- and 10-sen pieces also became aluminum in 1940.

France, Al. 1-Franc, 1941

Lebanon, 2 1/2-Piastres, nd (1944)

 After the war, the coinages of many countries included aluminum coins, particularly those of the Third World, the French possessions and Iron Curtain countries. In many cases, aluminum is also used as a constituent in different alloys. But it seems destined to stay as inflation forces former higher-denomination coins to be struck more cheaply – and, for better or worse, it’s widely held that aluminum is pretty much the bottom of the barrel.


Previously printed in the MICC Numismatic Journal Vol-02, Issue-09