Diamonds are famous for their strength, but scientists have long suspected that another form of diamond might be even harder.

Scientists created a pure hexagonal diamond in the lab, confirming a long-debated carbon structure slightly harder than natural diamonds.

Several months ago, the Hope Diamond was taken from the National Museum of Natural History for an overnight stay in the mineralogy lab. Chip Clark / NMNH, SI At first, Evalyn Walsh McLean, an heiress ...

A Chinese research team has produced bulk hexagonal diamond, a crystal structure long theorized to be harder than ...

Diamonds are famous for their strength, but scientists have long suspected that another form of diamond might be even harder. Evidence of this was gathered over the past sixty years in meteorite ...