![]() ![]() Projecting into Lake Michigan is the Keweenaw Peninsula containing the Calumet, Hecla and Tamarack mines with shafts one mile (1.6 kilometres) deep. The chief copper district in the USA is the mineral range near the south shore of Lake Superior. The most famous copper mine in Britain was the Parys mine in Anglesey, near Amlwch, peaking at 5,000 tonnes a year. The Statue of Liberty in New York is an example of this. However, it loses its strength if "annealed" by being heated to a low red heat and quenched in cold water.Ĭopper architectural structures weather to give a green verdigris (or patina) coating which is copper carbonate - or, if near the sea, copper chloride. When rolled, hammered or drawn, copper becomes hard, almost as strong as mild steel. If kept well polished it is highly ornamental. COMPOUNDSĬopper compounds are known as the copper salts, azurite, malachite and turquoise, and have historically been used as pigments.Ĭopper does not react with water, but it does react slowly with oxygen to form a layer of brown-black copper oxide which, unlike rust on iron, protects the underlying copper from more extensive corrosion. The Bronze Age gave way to the Iron Age, as iron was easier to find and easier than bronze to process into a usable metal. This established the Bronze Age, which ended with the Iron Age in 600 BC in northern Europe. It was also the first metal to be purposefully alloyed with another metal, tin, to create bronze - around 3500 BC in India, Mesopotamia and Greece. Exhibited in the British Museum is a heavy copper pin that was discovered in an Egyptian tomb.īy 3500 BC, it was the first metal to be smelted from the ore and cast into a mould. ![]() Most copper is mined as mineral ores of sulphides (chalopcopy and chalcocite) but it can also be carbonates (azurite and malachite) or oxides (cuprite) HISTORYĪfter gold, copper was the first metal to be used by humans, around 8,000 BC and probably in the Middle East from that era. This article offers a non-technical background to copper, to accompany the section on Río Tinto mines. It is perhaps the most useful metal to man after iron. Copper can occur in nature in its pure form - called native copper - but usually it is found as a mineral ore. A freshly exposed surface of pure copper has a reddish/orange colour. ![]() It is a soft ductile metal with very high thermal and electrical conductivity. Copper is a metal and chemical element with the symbol Cu. ![]()
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