Mining in Cornwall and Devon tin was found as alluvial deposits of cassiterite in the gravels of stream beds. Eventually tin was mined underground; underground mines sprang up as early as the 16th century. Tin lodes were also found in outcroppings of cliffs. Tin is one of the earliest metals to have been exploited in Britain. Chalcolithic metal workers discovered that by putting a small proportion of tin (5 – 20%) in molten copper, the alloy bronze was produced. The alloy is harder than copper. The oldest production of tin-bronze is in Turkey about 3500 BC, but exploitation of the tin resources in Britain is
Sundown Tin and Copper Mine and were mined from different shafts. With rising prices the mine was operating again in 1897, and much development work was carried out in 1898. By 1899 a smelter must have been erected, as 470 tons of ore was smelted for 53 tons of matte containing 30% copper and 50oz silver per ton, and 20 men were employed. More ore was raised in 1900, but the mine was under exemption through 1901-1903, a time of low copper prices. In 1904 the mine was described as having an open-cut on the tin portion, and on the copper section a tramway ran