Station: [219] Metallurgy

Bronze was a much-coveted material. It gleams like gold but is hard, more resilient, and can be moulded in every way. These attributes made it possible to invent new products, or to adapt old ones. Thus it was, that the narrow-bladed long sword was invented during the Bronze Age.

At first, people used pure copper. In its natural state, copper occurs as an ore; the metal has to be extracted by smelting.  Copper ores are mainly found in the mountain areas of Europe. During the Bronze Age, copper ores from the Central Alps were used.  First, the copper-bearing minerals that lay close to the surface were quarried, which could easily be spotted by their colour. You can see some of these copper ores in the display case.  Later on, they had to resort to mining the ore that lay beneath the ground. That’s how active mining developed, as for instance, in Mitterberg, in the countryside around Salzburg in Austria.

Mining procedures were very strenuous. First, the ores had to be broken up, separated from the rough stone and roasted.  The copper ore was roasted with charcoal, and smelted to remove the impurities. The copper metal that was finally obtained was further refined by forging, and then put through another smelting process.  

People soon realised that the properties of copper could be improved by adding tin; the resulting alloy had a lower smelting point and poured better. Endurance and hardness could be adjusted, depending on what was required.

Tin deposits in Europe are rare; tin is mainly found as cassiterite, tinstone in watercourses. In such places, it can be panned, like gold. From the early Bronze Age onwards, the tin came from Cornwall, in South West Britain. The raw material was traded over great distances, and important news and skills were certainly exchanged all along the way.  The ceramic fragments in the display case here show that the large tin deposits in the Erzgebirge mountains were apparently also being used, from the later Bronze Age onwards. The sherds  came from an archaeological site near alluvial tin deposits close to Johanngeorgenstadt. Tin streaming involved washing soil containing  tin ore in flowing water. Wooden structures were built to regulate the flow of the water, to ensure that the heavy lumps of ore settled on the river bottom. Dead rock and earth were then washed away.