Speleothems

William R. Elliott, Ph.D.
Missouri Department of Conservation
March 26, 2002

A speleothem is a secondary mineral deposit in a cave, derived by a chemical reaction from berock or other materials (Aspelaion@ = cave, Athema@ = deposit in Greek.) In Missouri and many states it is illegal to remove, mark on, or damage these fragile speleothems or other cave resources without the owner=s written permission. Here are the more common types in Missouri.

anthodite--A cluster of needles or quill-like crystals.
aragonite--A crystalline form of CaCO3 (calcium carbonate), which usually crystallizes as needles. The second most common cave mineral after calcite.
boxwork--Intersecting mineral blades projecting from the walls or ceiling of a cave; can be calcite, gypsum, limonite, silica, or other minerals.
calcite--The most common cave mineral and the usual constituent of most speleothems; the trigonal polymorph of CaCO3 (calcium carbonate).
cave coral--A coral-like deposit with branching steams and nodular tips; formed by dripping or splashing water.
cave ice--Floating calcite crystals that look like ice forming on a pool. May cover an entire pool. May sink to the bottom as Acave rafts@.
cave pearl-- A carbonate concretion, often spherical, which forms in shallow cave pools.
column--A speleothem formed by the junction of a stalactite with the stalagmite below it.
drapery, curtain, bacon--A folded or furled speleothem that hangs down from inclined walls or ceilings.
flowstone--A smooth, sheet-like deposit formed by films of flowing water on walls and slopes.
gypsum flower--A deposit, usually calcium sulfate, which grows from the base with petals that curve radially outward from the center.
helictite--A twisted speleothem, which grows via a small capillary canal. Varies from straight to antler-like and other forms.
rimstone, gour--A dam or rim that forms at the edges of pools, where calcite crystals collect. They can range from a fraction of an inch to several feet high.
spathite--An aragonite, tubular stalactite consisting of a vertical succession of small, petal-shaped, thin-walled cones. Sort of a bell-bottomed soda straw. Common in the Ozarks, for some reason.
stalactiflat--A shelf of flowstone attached to a stalactite; deposited on a former clay or gravel fill, now removed. Canopies, false floors, and hanging bathtubs are related forms that grew over now-missing banks. Such forms, common in the Ozark region, indicate a long cave history.
stalactite, soda straw--A vertically-hanging speleothem formed by dripping water and generally having a tube or its remnant at the center.
stalagmite--A vertically-oriented convex floor or ledge deposit formed by dripping water.


Further Reading: See Caving Basics (NSS), Cave Minerals of the World (Hill & Forti, NSS), or Speleology (Moore & Sullivan, Cave Books).