Tin sources and trade in ancient times Bantu culture of Zimbabwe are known to have actively mined, smelted and traded tin between the 11th and 15th centuries AD . Tin deposits exist in many parts of South America, with minor deposits in southern Peru, Colombia, Brazil, and northwestern Argentina, and major deposits of exploitable cassiterite in northern Bolivia. These deposits were exploited as early as 1000 AD in the manufacture of tin bronze by Andean cultures, including the later Inca Empire, which considered tin bronze the "imperial alloy". In North America, the only known exploitable source of tin during ancient times is located in the Zacatecas tin
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