Gypsum caves, while rare, are not unheard of, even in the United States. For example, South Dakota's dazzling Jewel Cave National Monument is rich in gypsum crystals. But Alabaster Caverns stands ...

In 1993, while exploring a 77-mile-long gypsum cave in Ukraine, Nicola found a secret that had nothing to do with geology: a chamber where 20th-century people had clearly lived for some time.

Geologist Juan Manuel García-Ruiz calls it "the Sistine Chapel of crystals," but Superman could call it home. A sort of south-of-the-border Fortress of Solitude, Mexico's Cueva de los Cristales ...

Then there is Gypsum Cave, an important ceremonial site for Southern Paiute people that also contained some of the earliest evidence of human inhabitants and Ice Age “megafauna,” or large ...

This cave had clearly built itself from the bottom up, rather than the top down. The ancient chemical soup had deposited not only deep beds of gypsum but also sulfur, manganese, iron, and other ...

Cahill, who described himself as an avid caver, took almost every precaution he could think of when he entered the 4.5-mile gypsum cave near Carlsbad Caverns National Park at about 5 p.m. the ...

The highlight of the expansive park is the 3/4-mile alabaster cave, which is the world's largest natural gypsum cave. This ...

Gripping a rocky ledge deep underground, Rick Toomey lowered himself gingerly down a 12-foot drop-off in Mammoth Cave, his headlamp flashing past rock walls dotted with sparkling gypsum in a ...

which praises the caves for their "long passages with huge chambers, vertical shafts, stalagmites and stalactites, splendid forms of beautiful gypsum flowers, delicate gypsum needles [and] rare ...