where is tin found? Also copper?
If at the start of the bronze age; 2000-3000 BC, up until then humans used stone and wood. How did these same humans process tin from the rock in which it is found? Did they crush the stones with the rocks or the wood? And why would they even want to get the different colors (tin) from a rock buried deep in the ground. Who told them in order to make bronze they needed 90 % copper and 10% tin to mix together to produce bronze? Copper is fairly common through the world, but tin is only found...Where?