Diamonds—they may be forever, but they're not indestructible. Although, as demonstrated by Dr. Peter Wothers in the video below, it does take an awful lot to make them burn.

Purely consisting of repetitively connected structures of carbon atoms covalently bonded to four other carbon atoms, diamond is a form of pure carbon, or allotrope, like graphite. But if you held a diamond over a candle flame under normal conditions, pyromaniacs out there will be disappointed to see that it won’t burn.

However, in the name of science, of course, researchers can get their hands on a lot more than a meagre candle to prove a point. But to showcase this, Dr. Wothers first needed to find a diamond. Reputation at stake, Wothers didn't fancy a bank heist. Well, how about Nobel Prize winner Harry Kroto’s engagement ring?

In this demonstration from the 2012 Christmas Lectures of The Royal Institution, Dr. Wothers surrounds Kroto’s engagement ring with pure oxygen and makes it burn like a fiery sun.

While the waveringly jovial face of Kroto’s wife sitting amongst the audience is almost painful, it’s all revealed to be a prank—the ring is perfectly fine.

[H/T io9]