The pressure’s on: making diamonds that are harder than diamond

Imagine telling your boss that you need to spend $1000 each on two diamonds – for work. But you will use them to create more diamonds!  The catch? You will probably break them in the process (so maybe we’d better get some spares).

In this talk Professor Jodie Bradby takes us into her research into high pressure materials, especially diamonds.

Creating these high-pressure experiments relies on the hardest material – diamond – which enables her group use to explore the formation of more diamonds. This includes a harder form called Lonsdaleite, made with a hexagonal arrangement of carbon atoms (instead of the cubic pattern in normal diamonds) and is predicted to be 50% harder.

But the process is fraught – she knows the sound of a diamond cracking all too well. Luckily, diamonds confiscated from smugglers – which cannot be re-sold – can be used for science, which cuts the otherwise “eye-wateringly high” costs.

In this talk Professor Bradby relates her success stories – turning a graphite sample into a transparent diamond (“imagine looking through a pencil”) and how they proved they had indeed made Lonsdaleite.

If all this effort to create gemstones seems frivolous, Professor Bradby reminds us that diamonds drills are widely used in industry and a hard, lonsdaleite tip would be a massive boon.

Sixties research into making diamonds has led us to a place where, instead of diamond presses, chemical vapour deposition is used to create diamonds (“a machine that looks a bit like a microwave”) and Professor Bradby hopes her research will lead to much more attainable Lonsdaleite too.


Prof Jodie Bradby
T: (02)61254916

Updated:  27 November 2021/ Responsible Officer:  Director, RSPhys/ Page Contact:  Physics Webmaster