lonsdaleite

Lonsdaleite is a rare and exotic form of carbon, closely related to diamond but with a different crystal structure. It’s named after British crystallographer Kathleen Lonsdale, who was the first to suggest its existence in the 1940s, though it was only confirmed later. Lonsdaleite’s structure is hexagonal, compared to diamond’s cubic structure, which is part of what gives it its unique properties.

It is thought to form in meteorite impacts, where extreme pressure and temperature conditions create the hexagonal arrangement of carbon atoms. Due to this rare formation process, lonsdaleite is considered even harder than diamond in certain directions. It’s incredibly difficult to find and even harder to study because of its scarcity.