The Cave of Crystals, Naica Mine in Mexico

The Naica Mine of the Mexican state of Chihuahua is a working mine that is best known for its extraordinary selenite crystals. The Cave of Crystals (Cueva de los Cristales) is a cave approximately 1,000 feet (300 m) below the surface in the limestone host rock of the mine. The chamber contains giant selenite crystals, some of the largest natural crystals ever found.T he selenite crystals were formed by hydrothermal fluids emanating from the magma chambers below