On top of it, the marketplace for diamonds can be really confusing. There are grades of clarity and color that lead to an overall quality rating. And, of course, diamonds are very expensive. 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 ...

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, ...