Tin

Tin is scarce and rarely found near copper, so the Bronze Age depended on long-distance trade — Cornish tin reached the Mediterranean by routes that were old before Rome. Tin has more stable isotopes than any other element, ten of them, a consequence of its magic proton number of 50. It also has a famous vice: below 13.2 °C white tin slowly converts to brittle grey tin, which occupies more volume and crumbles to powder, a transformation called tin pest that has been blamed for the leaking fuel cans on Scott's Antarctic expedition and for organ pipes disintegrating in cold European churches. Tin cans are steel with a few microns of tin plating. And every sheet of window glass in the world is made by floating molten glass on a bath of molten tin, the process Alastair Pilkington invented in 1952.