HOW LONSDALEITE FORMED NATURALLY

A look at how this ultra-hard diamond emerged in a meteorite

1 Mantle formation

High temperatures in a dwarf planet's mantle caused a fluid mix of carbon, hydrogen, oxygen and sulphur to become heated and pressurised.

3 Mixing with graphite

As the chemical mix was released, it interacted with the graphite crystals and caused them to be replaced by lonsdaleite.

2 A collision

An asteroid impact smashed the mantle – an event taking place about 4.5 billion years ago. Pressure and temperature dropped in the immediate aftermath.

4 To Earth

Ureilites – meteorites thought to have originated in the mantle of a dwarf planet – came to Earth, where they were later found and examined.