Early Tin Mining in South West England

I have found some information about early tin mining in South West England, ie Cornwall and west Devon. Tin is a vital element, used as a strengthening metal with copper to make the alloy bronze, from which the Bronze Ages were named.

Tin ore is normally found in granite outcrops. In this area of the country they are, Land`s End, Carnmenellis, St Austell Moor, and Bodmin Moor in Cornwall and Dartmoor in west Devon. It is reasonable to presume that these would have been the main tin mining areas in the Bronze Ages. In fact until this century this area of Cornwall and west Devon was a principle source of tin and copper to at least the British Isles for a perhaps uninterrupted period of over three and half thousand years.

Tin is usually present in its natural state as tin ore or cassiterite. Cassiterite is a chemically stable, heavy and durable mineral. It is usually stained brown to black by iron impurities in the rock. There is a rarer tin mineral from which the ore can be obtained called stannite. Stannite weathers to a form of tin oxide known as "wood-tin".

Heavy weathering and erosion causes the granite from which the tin ore is obtained to wear away and the cassiterite often settles into the base of a stream. These are known as "tin streams". Tin streams were thought to have been a basis for obtaining tin in the Bronze Ages. The early prospector would collect pebbles made of cassiterite from the bed of the stream. A cashe of stream tin was discovered at a Bronze Age settlement at Trevisker Round, St Eval, Cornwall. This cache consisted of grey-brown pebbles of stream cassiterite, 10 to 15 mm in diameter. They would have been ideal for smelting to tin.

It is interesting that although in this country tin was normally only a proportion of 10% of bronze, the rest being made of copper. In Saxony and Bohemia a white bronzes have been found containing up to a 27% proportion of tin.

There have been thought to be ancient routes where the tin and other valuables for trade would have been sent from Cornwall to traders in Ireland and Europe. A route from Harlyn Bay, near Padstow in north Cornwall, to the sea south of St. Austell, has been considered as a trading path across Cornwall, linking Ireland to Brittany and the Continent. A route is also considered to have been from St. Ives Bay to Marazion. This latter route would avoid navigation around Land's End. Many archaeological artefacts from the Early Bronze Age have been found in these areas supporting this theory. At Harlyn Bay two gold lunulae have been found. Lunulea are crescent shaped sheets of gold, usually 20 cm across. They were thought to be worn on the chest, similar to a modern broach. An almost identical decorated golden lunula to the Harlyn Bay one has been found at Bourbriac, Brittany. It is thought that they were both produced by the same craftsman. This suggests that there was a trade route between the two areas. There was also a flat axe of an Irish or Breton type found at Harlyn Bay, which could have been part of a trading package. Tin when mined would have been traded along these routes.

Cornwall and west Devon can be considered to be a major supplier of tin to Europe in the Early Bronze Age.