Tin is an essential metal in the creation of tin bronzes, and its acquisition was an important part of ancient cultures from the Bronze Age onward. Its use began in the Middle East and the Balkans around 3000 BC. Tin is a relatively rare element in the Earth's crust, with about 2 parts per million (ppm), compared to iron with 50,000 ppm, copper with 70 ppm, lead with 16 ppm, arsenic with 5 ppm, silver with 0.1 ppm, and gold with 0.005 ppm. Ancient sources of tin were therefore rare, and the metal usually had to be traded over very long distances to meet demand in areas which lacked tin deposits.
The importance of tin to the success of Bronze Age cultures and the scarcity of the resource offers a glimpse into that time period's trade and cultural interactions, and has therefore been the focus of intense archaeological studies. However, a number of problems have plagued the study of ancient tin such as the limited archaeological remains of placer mining, the destruction of ancient mines by modern mining operations, and the poor preservation of pure tin objects due to tin disease or tin pest. These problems are compounded by the difficulty in provenancing tin objects and ores to their geological deposits using isotopic or trace element analyses. Current archaeological debate is concerned with the origins of tin in the earliest Bronze Age cultures of the Near East.