Diamonds are made out of carbon — highly organized carbon, that is. Geologists are still guessing how diamonds formed in the ...

A pair of diamonds that formed hundreds of kilometers deep in Earth’s malleable mantle both contain specks of materials that form in completely opposing chemical environments—a combination so unusual ...

Formed millions to billions of years ago, diamonds can shine light into the darkest and oldest parts of the Earth's mantle. The analysis of ancient, superdeep diamonds dug up from mines in Brazil and ...