The crew, who were mining for ore deposits, uncovered a vast cavern in the limestone rock of the mine, filled with some of the largest crystals ever discovered on the planet: giant selenite ...

The chamber contains giant selenite crystals (gypsum, CaSO₄·2H₂O.), some of the largest natural crystals ever found. The largest is 11.40 meters (37.4 ft), with a volume of about 5 cubic ...

Previously, the world’s largest examples of selenite crystals came from a nearby cavern discovered in 1910 within the same Naica cave complex. Several examples from the Cave of Swords are ...