Cave of the Crystals

The Cave of the Crystals is a natural marvel in Chihuahua, Mexico. Its main chamber houses some of the largest natural crystals ever discovered, hence the name. The magma within makes the cave unbearably hot and humid, and thus it remains largely unexplored. Nevertheless, this subterranean spectacle is unquestionably one of the world’s most remarkable displays of natural mineral formations.

Cave of the Crystals Facts

The Cave of the Crystals is connected to the Naica Mine, 300m (980 ft.) below the ground in Naica, Chihuahua, Mexico. Despite the Naica Mine having been worked for centuries, the Cave of the Crystals remained undiscovered until the year 2000, when two miners, pursuing traces of silver, broke into the extensive subterranean chamber. Just days later, an iron door was erected in order to protect the entrance.

Whilst the cave is referred to singularly, as the ‘Cave of the Crystals’ (Cueva de los Cristales), it is in fact made up of three co-joined caves, with one far larger than the others.

This gigantic cavern is home to towering stacks of selenite; rising so tall that humans appear miniscule in comparison. In fact, the tallest crystals have been measured at 11m (36 ft.) high, weighing approximately 55 tonnes.

These giant crystals have experienced steady slow growth over the past half a million years. Approximately 2-3 miles (3-5km) under the surface is a giant pool of magma. The caverns became flooded over time as a result of groundwater seeping in. This water was rich in gypsum minerals, and the heat generated by the magma worked like a cooker, maintaining a steady heat for 500,000 years. The gypsum in the water then transformed into the translucent selenite crystals that we see today. Whilst up until now the crystals have grown steadily and slowly, they will grow no further unless the cave floods once again.

Beneath the cave lies a pool of magma, rising up from the Earth’s core. This heat from this magma makes the cave unbearable for any substantial amount of time. In fact, no human can spend more than a mere few minutes inside the cave. Temperatures of 150°F (65.6°C) have been recorded in the main chamber, whilst the smaller caverns are slightly cooler at 100°F (37.8°C). To add an extra layer of danger, conditions are close to 100% relative humidity.

The story of a miner who managed to bypass the protective iron door illustrates the aforementioned risks perfectly. Despite knowing the risks, he had entered the chamber with plastic bags filled with air. This, he hoped, would buy himself enough time to enter and steal some of the precious crystals within. Alas, the man was found dead the next day; cooked, as though he were food in an oven.

The Naica mine is still active, and should you wish to visit, it is possible to do so with prior approval. However, bear in mind that only the upper caverns are available for access (under supervision), with the lower caverns currently considered too dangerous due to extreme temperatures. Only scientists and employees are able to access these prohibited areas.