A century ago crude oil was the most valuable substance on the planet, but the coronavirus pandemic has caused the price per barrel to plummet. But how have the likes of diamonds, gold, and platinum fared? Rarer substances such as painite and the chemical Californium 252 are among a host of other obscure materials you’ve probably never heard of that command a high price for the fact they’re ultra-rare, hard to extract or valued for highly unique properties. Click or scroll through to discover the most valuable substances on Earth, based on prices at the time of writing (28 April 2020).