The Erzgebirge or Ore Mountains form the boundary between Germany and the Czech Republic, crossing the old regions of Saxony and Bohemia. Since the Middle Ages, the area has been known for its rich metal ores, and the development of mining. The valley of Saint Joachim, or Joachimsthal, (Jáchymov in Czech) is one of the most important sites. Its history shows the complicated connections between science, technology and a changing society over the last 500 years.

Silver Dollars

When large amounts of silver were discovered here in 1516, the local landowner, Count von Schlick, quickly took control of what became a mining boomtown, with a population which soon reached a peak of 12,000 people. He got permission to mint silver coins, which had an image of Saint Joachim on one side and the Count, King, or Bohemian lion on the other. These coins were known as Joachimsthaler Groschen which was quickly shortened to Joachimsthaler, then Thaler. These coins were so reliable that the term 'thaler' spread through Europe, and changed to 'dollar' in the Netherlands. 200 years later, when the USA launched its own currency, the familiar name 'dollar' was chosen.

By 1545, the Joachimsthal mines had been completely taken over by Frederick, King of Bohemia. At its height, production reached a peak of 14 tonnes of silver a year. Soon, however, competition from New World silver cut into the mines' profits, and the lack of pumps made deeper mining difficult. By the time of the Thirty Years War production was low, and from then on the amounts of silver produced were fairly minor.

Agricola - a Pioneer of Metallurgy

Georg Bauer was born in Saxony in 1494. His surname meant 'Farmer' so he was better known by the Latin form of his name, Georgius Agricola. He studied medicine, and in 1527 was appointed doctor for the town of Joachimsthal. In the three years he spent there, he occupied all his spare time with the study of mining, and from 1530 to 1533 he spent his time travelling for further research. He then settled in Chemnitz in Saxony, where he published a large number of works, including De Re Metallica, a classic which is regarded as the foundation of modern metallurgy. Unfortunately, publishing in Latin (as was the standard at the time), meant that he had to invent a huge number of technical terms, which makes his work hard to follow nowadays¹.

The Erzgebirge remained a centre of metallurgy and practical mining knowledge over the next few hundred years. The first documented Western use of explosives in mining took place in this region in 1627.

Cobalt and the Gnomes

The ores of the Erzgebirge contained a number of other metals besides silver. To the early miners, these were a source of frustration: cobalt ores were seen as a useless imitation of silver, pawned off by the malicious Kobolds or gnomes that were thought to live in the mines. Nickel ore, which looked frustratingly like copper, was known as Kupfernickel (Old Nick's copper), blaming the devil for replacing copper with this worthless ore. When they were isolated in the 18th Century, both cobalt (1735) and nickel (1751) were named from the terms used by the superstitious miners. In the 19th Century, cobalt from Joachimsthal was used to make the expensive pigment 'cobalt blue' used for both painting and ceramics.

Uranium in a Minor Role

The Joachimsthal mines produced a heavy black ore known as pitchblende. In 1789, a German chemist called Martin Klaproth purified a new metal from this previously worthless ore. He called his new element uranium, in honour of the planet Uranus which had recently been discovered. This minor metal had a commercial importance, as its compounds could be used to colour both pottery glazes and glass. In the 19th Century, the Imperial chemical factories were an important part of the economy of the valley, and the 'uranium yellow' was a Bohemian monopoly. Silver was still being mined, along with tin, cobalt, bismuth, and even arsenic.

Marie Curie and Radioactivity

In 1896, Becquerel discovered the phenomenon of radioactivity in uranium. In Paris, Marie Curie began to study radioactivity. In 1898, using some of the pitchblende from Joachimsthal as raw material, she identifed the new elements radium and polonium. By 1902, she had painstakingly isolated a tiny amount of radium. This was regarded as a triumph for French science, and made Curie a role model for 20th Century women. Radium was investigated for medical uses, and was soon in high demand. Meanwhile, the Austrian government, conscious of the possible importance of the new element, set up what they hoped would be a monopoly of pitchblende production. Since other countries soon discovered uranium ores, this monopoly never became reality.

Shifting Borders and the Arms Race

At the end of the First World War, Joachimsthal became part of an independent Czechoslovakia, though the area remained mostly German-speaking, with strong links to the Saxon miners on the other side of the border with Germany. Under the new regime the old name 'Joachimsthal' was replaced by 'Jáchymov'. During the 1920s and 1930s, the mines produced about 10 tonnes of uranium compounds a year, with barely three grammes of radium. When Germany took over the Sudetenland in 1938, the mines of the Erzgebirge were a particularly valuable prize. Both Germany and its opponents, in the run-up to World War II, began the experiments which would eventually lead to the production of an atomic bomb using uranium.

In 1945, the old border was restored. Between 1945 and 1948, the German-speaking people of the Sudetenland were expelled. Czechoslovakia soon came under Russian domination, and a large prison camp was set up in the valley of Jáchymov. The mines were now run using thousands of mainly political prisoners, producing uranium for Russian bombs. The mines were closed in 1963, and Jáchymov is now a quiet city in a quiet valley.

The Lingering Spectre of Health Risks

The mines of Joachimsthal (and the corresponding mines over the border in Saxony) were always known to be unhealthy. A curiosity of the 18th century Erzgebirge mines was that the miners' hair sometimes took a blue tone from the levels of cobalt compounds. More seriously, the miners tended to die from lung cancer at startling rates. In the 1930s this was studied and quantified, and the 40% mortality rate rang alarm bells for many people dealing with radioactive materials. Cynically, this was one reason why prisoners were used in the mines in the 1950s. Modern studies blame this cancer rate on the high levels of radon gas, whose insidious effects are a problem in many parts of the world.

In the early 20th century, Radium was such a startling novelty that all kinds of health benefits were attributed to it. The valley of Joachimsthal saw the foundation of spas and 'health' resorts, where the radioactive waters and vapours were thought to cure all kinds of diseases. Sadly, any effect on the patients is likely to have been harmful. This strange association of health spas with an old industrial landscape still exists in Jáchymov today, where the radioactive spa wells are advertised as one of the tourist attractions.

Even the uranium glazes that once gave rich colours to pottery are now considered dangerous. Since the heavy metal can be leached out by acids like fruit juices and salad dressings, these glazes are considered unsafe to use anywhere near food. Nevertheless, from dollars to radon detectors, there are still many reminders around us of the historic importance of the Joachimsthal mines.