It took nearly two centuries for palladium's significance to be recognised - and the fight against global pollution owes a lot to this unique metal.

Following the perfection of his technique to obtain pure samples of platinum in 1801, William Hyde Wollaston went on to isolate palladium two years later by dissolving platinum ore in aqua regia (a mixture of hydrochloric and nitric acid). He named it after Pallas, the ancient Greek goddess of wisdom whose name had also been recently lent to the second asteroid ever discovered.

In an attempt to keep his techniques a secret, Wollaston offered samples of palladium for sale anonymously and his peers were cynical about the new metal's provenance, suspecting that it was an alloy of platinum. This forced him to publish details of his findings in 1805.

The use of palladium really took off in the 1970s when demand for catalytic converters - in which its remarkable properties play a key role - increased as automobile emission standards were introduced in the developed world. As these standards were tightened and applied globally in the 90s, demand for palladium expanded exponentially.