Jeweler Harry Winston donated the famous Hope Diamond—the largest-known deep blue diamond in the world—to the Smithsonian Institution in 1958. It arrived in a plain brown package by registered mail, ...

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

They don’t make them like they used to — at all. It can take natural diamonds over three billion years to grow, but researchers in a South Korean lab have successfully fabricated the precious stones ...

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 ...

Very few gems can withstand the intense pressure of Earth's mantle, but some require it to crystallize. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it ...

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 ...