I n 1910, in Naica, Chihuahua, Mexico, a group of miners discovered a cavern beneath the Naica mine workings. It was named the Cave of Swords. In April 2000, while miners were excavating a new tunnel, drilling through the Naica fault line, they discovered another cave which was named Cave of Crystals or Giant Crystal Cave.
Brilliant beams
The Cave of Crystals is a horseshoe-shaped cavity in limestone. Its floor is covered with perfectly faceted crystalline blocks. Huge crystal beams jut out from both the blocks and the floor. The caves are accessible today because the mining company’s pumping operations keep them clear of water. If the pumping were stopped, the caves would again be submerged in water. The crystals deteriorate in air, so the Naica Project is attempting to visually document the crystals before they deteriorate.
Two other smaller caverns were also discovered in 2000, Queen’s Eye Cave and Candles Cave, and a further chamber name Ice Palace, was found in a drilling project in 2009.
Inside the cave, it is hot and humid as it has been for almost 500,000 years, resting on the magma of the earliest fault line. As the magma cooled, water temperature inside the cave increased to 58° Celsius. The water was found to contain a mineral called anhydrite. As a result of the constant heat, the anhydrite gradually liquefied into gypsum. Being a soft mineral, gypsum developed into crystals.
The constant presence of water inside the cave gave rise to pillars of crystal beams crossing each other. The crystals are massive, but they are fragile and even a scratch can damage them.
Other caves under the mountain range, witnessed temperature changes and formed smaller crystals. In contrast, massive crystals developed in Cave of the Crystals because of the presence of water and steady temperature.
The temperature inside the cave being 58° C, ice packs on the chest, pockets and on the back are essential. An added vest is vital to keep the ice protected against the blazing heat. A caving suit, helmet, respirator mask along with a headlamp, gloves and boots completes the attire. In spite of this, it is impossible to stay inside the cave for more than 20 minutes.
The pillar formation was an ongoing process until 1985 when miners accidentally emptied water from the cave. Without the water, combined with exposure to air, the crystals may not last long. Apart from this, other atmospheric gases can affect the crystals. In order to preserve the cave, a steel door has been installed.
