News Chemistry

A new method of making diamonds doesn’t require extreme pressure 

Lab-grown diamonds formed without a squeeze in a liquid of gallium, iron, nickel and silicon

Four diamonds of varying hues are shown on a black background

Lab-grown diamonds (some pictured) can be made in liquid metal at high pressure. A new technique makes diamonds at atmospheric pressure.

LIONEL BONAVENTURE/AFP via Getty Images

By Emily Conover

Diamonds in nature famously form under immense pressure in Earth’s mantle. But a new laboratory technique allows diamonds to skip the squeeze. 

The most common method for producing synthetic diamonds, known as high-pressure and high-temperature growth, or HPHT, requires around 5 gigapascals of pressure, similar to that in the upper mantle where diamonds form naturally.