Gold vs Platinum

Gold objects buried more than six thousand years ago come out of the ground as bright as the day they were made. That single property, a near total refusal to react with air or water, explains almost everything about gold's place in history. It could be found as pure metal in riverbeds, shaped without a furnace, and it never lost its shine. So it became ornament, then money, then the standard against which money was measured.

• All the gold ever mined, well over 200,000 tonnes, would fit in a cube roughly 22 metres on each side.
• Gold is so malleable that a single gram can be beaten into a sheet about a square metre in area, and gold leaf is thin enough for greenish light to pass through it.

Platinum is a dense, silvery white metal that almost nothing will react with. It does not tarnish, it is not touched by single acids, and it stays bright in a furnace where silver would melt. Its name comes from the Spanish platina, little silver, a slightly dismissive nickname from colonists in South America who found it mixed with their gold and had no idea what to do with it.

• Platinum is mined at only a fraction of the rate of gold; world mine output is a couple of hundred tonnes a year, compared with several thousand tonnes of gold.
• The anti-cancer drug cisplatin was discovered by accident in the 1960s when bacteria near platinum electrodes stopped dividing.