When it comes to natural materials, it doesn't get much harder than diamond. The carbon-based material can be used to cut through steel, wood and glass, and, under normal circumstances, it's so hard that it can't be burnt. But in this British Royal Institution experiment, scientist Peter Wothers shows that there is a pretty neat way to destroy diamond, and he plays a cool little prank on Nobel prize-winning chemist Sir Harry Kroto in the process.
In the set-up, Wothers recreates a pretty standard experiment for testing whether a material contains carbon, which involves burning it in a chamber with pure oxygen. But he then adds an interesting twist, by collecting the gas that's released in a tube and running it through limewater. If the material being burnt contains carbon, the resulting smoke will contain carbon dioxide, and when this meets the limewater it'll produce calcium carbonate and turn the whole thing milky white.
Wothers first demonstrates this with some graphite, but then takes things to the next level by performing the same experiment on a diamond taken from Kroto's wife's ring. Incredibly, the entire diamond sets alight, and, without producing any flames, glows like an mini-Sun. It's beautiful, but pretty terrifying for Kroto.
You'll have to watch the experiment above to see what happens next. We don't want to spoil anything, but we will say that Kroto is an incredibly good sport.
Hat tip to io9 for digging up the video.