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

(CNN) — Pink diamonds are extremely rare and coveted — a now-closed mine in Australia has been the source of 90% of the colored gemstones. Polished pink specimens of the highest grade can sell for ...

Washington, DC--New research from a team including Carnegie's Steven Shirey and Jianhua Wang explains how the world's biggest and most-valuable diamonds formed--from metallic liquid deep inside ...

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 ...

Diamond, with its tough-to-break carbon lattice of interlocking cubes, is traditionally considered the hardest material on Earth. Yet a rare form of diamond known as lonsdaleite—a crystal with carbon ...