for National Geographic News
It's "the Sistine Chapel of crystals," says Juan Manuel García- Ruiz.
The geologist announced this week that he and a team of researchers have unlocked the mystery of just how the minerals in Mexico's Cueva de los Cristales (Cave of Crystals) achieved their monumental forms.
Buried a thousand feet (300 meters) below Naica mountain in the Chihuahuan Desert, the cave was discovered by two miners excavating a new tunnel for the Industrias Peñoles company in 2000.
The cave contains some of the largest natural crystals ever found: translucent gypsum beams measuring up to 36 feet (11 meters) long and weighing up to 55 tons.
"It's a natural marvel," said García-Ruiz, of the University of Granada in Spain.
To learn how the crystals grew to such gigantic sizes, García-Ruiz studied tiny pockets of fluid trapped inside.
The crystals, he said, thrived because they were submerged in mineral-rich water with a very narrow, stable temperature range—around 136 degrees Fahrenheit (58 degrees Celsius).
At this temperature the mineral anhydrite, which was abundant in the water, dissolved into gypsum, a soft mineral that can take the form of the crystals in the Naica cave.
The new findings appear in the April issue of the journal Geology.
(Related" "Photo in the News: Giant Crystal-Filled Cave Discovered in California" [September 26, 2006].)
The mining complex in Naica contains some of the world's largest deposits of silver, zinc, and lead.
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