Cave of Crystals

Executive summary by darmansjah

30-foot-long (9m) crystals half a million years old

The Crystals Palace

Protected by an ice-cooled suit, a researcher rappels into the cave of Crystals. Unlike most caves, the Mexican cavern is extremely hot, warmed by magma chambers underneath.

True Shapes

Explorers clamber through the enormous selenite crystals that sprout from every surface of the Cave of Crystals. Scientists call the crystals’ sharp, regular shapes “euhedral,” from the Greek words meaning “true shape.”

MEXICO Some of the glittering giants of Cueva de los Cristales, or Cave of Crystals, are more than 30 feet long (9m) and half a million years old. But humans discovered the monly in 2000, when two brothers were drilling nearly a thousand feet (305 m) belowe ground in the Naica mine, south of Chihuahua in northern Mexico. Crystals embody order, with stacks of molecules assembled according to rigid rules. For eons, groundwater saturated with calcium sulfate filtered through the many caves at Naica, warmed by the magma below. As the magma cooled, water temperature eventually stabilized at around 136ᵒF (58ᵒC). minerals in the water converted to selenite, molecules of which were laid down like tiny bricks over the millennia to form these massive crystals.

Explained by science

For more than half a million years, mineral-rich water filtered through this cavern under Naica mountain, depositing molecules of calcium sulfate in orderly stacks. Heated by magma deep below and insulated by thick walls, the watery womb remained virtually unchanged, allowing crystals to grow to immense proportions.

The naica mine

Veined with ore deposits rich in lead and silver, the Naica mine would flood if the water table were not lowered by constant pumping. This action also drained the Cave of Crystals. The mine holds similar caves with samller crystals, named for the shape of their formations: Cave of Swords, Cave of Candles, and Eye of the Queen.

Temperature Inside the Cave

Readings have dropped about six degrees since its 2000 discovery because of the mine’s ventilation system.

How the megacrystals formed

25 million years ago Volcanic activity pushes magma toward the surface. Intrusions of mineral-rich fluid will be transformed into one bodies and mineral that later from the crystals

1-2 million years ago Temperatures underground decline and caves form, filled with mineral-rich water. Anhydrite, a type of calcium sulfate, begins to dissolve into the cave water.

600,000 years ago The cave cools to roughly 136ᵒF (58ᵒC), the right temperature for calcium sulfate in the water to form selenite crystals. Undisturbed, it becomes a nursery for giants.

Ca 1985 Miners unknowingly drain the cave as they lower the water table in the mine with pumps. No longer immersed in water, the crystals stop growing.