CaSO4 · 2 H2O), some of the largest natural crystals ever found on Earth. It’s a unique place — let’s have a look at how these colossal crystals came to be and what makes them so unique.

Discovered in 1999 inside an abandoned mine in Southern Spain, Pulpí Geode is the largest crystal 'cave' of its kind in the world. But what exactly is a geode and how do crystals form inside them?

The largest snow crystal ever measured was 10 millimetres across, discovered by Kenneth Libbrecht, who photographed the record-breaker in Ontario, Canada, in December 2003. Libbrecht is a ...