<P> 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 ( Valera & Valera 2003 , p. 10 ) . 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 . </P>
<P> 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 ( Valera & Valera 2003 , p. 10 ) . 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 . </P>
where did copper come from for bronze age
where did copper come from for bronze age
the Earth 's crust
the Earth 's crust