Diamonds form deep within the Earth's mantle, around 250 kilometers below the surface, where immense pressure (up to 10 GPa) and temperatures (around 2,200 °C) compress carbon into diamonds over ...

Dale Vince, who is also founder of green energy provider Ecotricity, says his lab-grown diamonds are environmentally friendly because they are made using carbon drawn from the air. Vince’s new venture ...