Scientists have discovered “young diamonds” formed more recently, which means the planet is still capable of creating extreme heat.

Diamonds are formed under extreme temperatures and pressures generated by certain volcanic events, previously thought to have existed early in the Earth's history. 

However, researchers from Vrije Universiteit Amsterdam found diamonds around one billion years old after analyzing 26 diamonds donated by De Beers Group based in Johannesburg, South Africa.

In the study published in scientific journal Nature Communications on Thursday, two populations were introduced as the results of the analysis. Nine of the rocks were from the Archaean age, about 2.95 billion years ago. Ten others were around one billion years old belonging to the  Proterozoic age, correlating with the volcanic event at Umkondo in southern Zimbabwe.

To determine the ages of the diamonds, the researchers dated garnet, a kind of mineral trapped in the rocks, using Sm-Nd isotope techniques, methods that determine the age relationships of rocks and meteorites.

"Conventional thinking has been that the level of melting needed to create these diamonds could only happen early in the history of the Earth when it was much hotter. We show that this is not the case and that some harzburgitic diamonds are much younger than assumed," Janne Koornneef, who led the study, told Phys.org. "We propose that our younger set of diamonds formed in a special environment where a major plume from the deep mantle was raised towards the surface and underwent extensive melting as the pressure reduced."

(Top photo: Electron microprobe images of garnet inclusions showing diamond imposed cubo-octahedral morphology and syngenetic growth features. (a) Garnet inclusion V471. The surface of V471 (b) has diamond-like “trigons” that establish syngenetic growth of inclusion and host. (c) Inclusion V445. The top surface of V405 (d) records stepped features and the side faces show well-developed growth lines consistent with syngenetic growth with the host diamond. /Nature Communications Photo)