Carlsbad Caverns Minerals
Photograph by Michael Nichols
Mineral deposits in Lechuguilla Cave take on fantastical forms in Carlsbad Caverns National Park, New Mexico. Stalactites of calcite and a small aragonite formation appear as if in a magical backdrop. Calcite and aragonite are the two crystal forms of calcium carbonate, a property of minerals geologists call dimorphism. Their crystal structure sets them apart: calcite forms hexagons and aragonite forms rhombohedrons.