Elemental sulfur in caves of the Guadalupe Mountains, New Mexico
— Kimberley I. Cunningham, Harvey R. DuChene, and Charles E. Spirakis

Elemental (native) sulfur occurs in at least three caves in the Guadalupe Mountains of New Mexico, including Carlsbad Cavern, Cottonwood Cave and Lechuguilla Cave. Sulfur in Carlsbad Cavern has been found at four sites. The sulfur is typicall  finely crystalline and occurs as sprays, rosettes or crusts that overlie latestage speleothems or bedrock. However, the sites in Cottonwood Cave are significantly different: a ceilingbound, multi-ton, massive deposit has a waxy luster and conchoidal fracture, whereas a nearby, smaller floor deposit is granular and admixed with massive gypsum. The three largest know  deposits in Lechuguilla Cave are multi-ton accumulations. Massive to slightly vuggy deposits occur in the lower part of the cave and platelike, vuggy deposits are found in higher parts of the cave. The well preserved relationship between the gypsum and sulfur in Lechuguilla Cave suggests that the sulfur was deposited inside preexisting gypsum masses. Lechuguilla Cave may contain more sulfur and related secondary gypsum than all other known caves in the world combined.