What is the chemical symbol for tin?

Sn, from the Latin stannum - another of the metals known in antiquity whose symbol does not match its English name. Tin is soft, low-melting and unremarkable alone, and it made the Bronze Age.

That is because bronze is copper with about ten per cent tin, and the two ores are almost never found together. Copper is common; tin is rare and concentrated in a few places - Cornwall, Anatolia, Afghanistan, and later Malaya - so making bronze required long-distance trade networks in a way nothing before it had. The Bronze Age was the first period in which distant societies depended on each other for a strategic material, and the collapse of those networks around 1200 BC is one of the leading explanations for the Bronze Age collapse itself.

It also has a strange failure mode. Below about 13 degrees Celsius, ordinary white tin slowly converts to a brittle grey powder - tin pest, which spreads through an object and crumbles it. It has been blamed, probably too neatly, for the buttons falling off Napoleon's army in the Russian winter; the effect is real, the story is almost certainly apocryphal. Modern lead-free solder has had to be formulated to suppress it.