-
Photograph by Carsten Peter, Speleoresearch & Films
Massive beams of selenite dwarf human explorers in Mexico’s Cave of Crystals, deep below the Chihuahuan Desert. Formed over millennia, these crystals are among the largest yet discovered on Earth.
-
Photograph by Carsten Peter, Speleoresearch & Films
Headed nearly a thousand feet underground, researchers descend by truck through a serpentine mine shaft.
-
Photograph by Carsten Peter, Speleoresearch & Films
Chewing out space for cables and pipes, workers toil in the Naica mine, where excavations in 2000 led to the chance discovery of the giant crystals. Several other chambers bearing smaller crystals have been found in Naica, Mexico’s most productive lead mine.
-
Photograph by Carsten Peter, Speleoresearch & Films
With temperatures in the Cave of Crystals spiking above 110°F, a researcher rappels down into it wearing an ice-cooled suit. Cavers first don a vest containing ice packs, then an insulated jacket to slow melting. Finally, they pull on a full jumpsuit. Breathing packs worn like backpacks pump ice-cooled air to a respirator mask, allowing the wearer to be cooled from within.
-
Photograph by Carsten Peter, Speleoresearch & Films
Gypsum crystals take on an abundance of forms in caves found throughout the Naica mine. The delicate structure here, found in the Cave of Candles, projects only a few inches from the cavern wall, a measure of refinement when compared to its car-size relatives in the nearby Cave of Crystals. According to Paolo Forti, a professor of geomorphology and speleology at the University of Bologna, several minerals have been found here that have never been seen inside caves before, including such tongue twisters as plumbojarosite, szmikite, and szomolnokite. “This system was really stable for a long time,” says Forti. “The caves here are astonishing.”
-
Photograph by Carsten Peter, Speleoresearch & Films
Perfect at least for now, luminous crystals face threats from foot traffic, looters, and condensation. Mine owners limit access to the cave, but researchers hope for legal protection.
-
Photograph by Carsten Peter, Speleoresearch & Films
Working slowly in the stifling heat, Italian physicist Giovanni Badino (at left) unwinds a tape measure while Stein-Erik Lauritzen, a geologist at the University of Bergen, collects core samples for uranium-thorium dating. The Cave of Crystal’s longest crystal measures 37.4 feet, and its oldest likely began growing some 600,000 years ago.
-
Photograph by Carsten Peter, Speleoresearch & Films
Outside the Cave of Crystals, documentary filmmakers and members of La Venta, an Italian exploration team, check their equipment before heading inside. La Venta designed the blaze-orange, ice-cooled suits to allow explorers and scientists to work longer and more comfortably in the cave’s severe heat. Most trips into the cave last 20 minutes or fewer, but fully suited explorers sometimes push the limit to 80 minutes—staying well after the ice has melted.
-
Photograph by Carsten Peter, Speleoresearch & Films
An air-conditioned tent offers heat-sapped explorers some relief.
-
Photograph by Carsten Peter, Speleoresearch & Films
Suffering is the price of admission where extreme temperatures mean cavers tire easily and risk potentially lethal heatstroke. La Venta’s Dr. Giuseppe Giovine (in helmet) checks vital signs after one trip, most of which last no more than 20 minutes.
-
Photograph by Carsten Peter, Speleoresearch & Films
Thick, blocky crystals line the interior of a cave called the Shark’s Mouth. Recently found not far from the Cave of Crystals, this cavern confirms the belief of geologists that numerous crystal-bearing deposits still await discovery in the rock. Because miners had been using explosives nearby, many crystals in the Shark’s Mouth were covered with dust.
-
Photograph by Carsten Peter, Speleoresearch & Films
Gypsum is relatively soft—as minerals go—and its sheetlike layers can be peeled with a fingernail or damaged by a clumsy kick. But for cavers climbing in a web of crystals, there is still the risk of a painful fall. Clusters of younger crystals along the walls and floor are angular and jagged, their edges as sharp as broken glass.
Buy NG Photos
Special Issues