Speleothems Photo Index

Speleothem is the general term used to describe all the kinds of minerals and formations that have been added to the cave after the void was formed. A similar term, speleogen is used for a shape carved into the rock as part of the formation of the cave. Sediment is the general term for the rocks that have fallen from the ceiling, rolled in the cave streams, and for the sand, mud, and clay that remain after the limestone has dissolved away. Most people are more interested in the speleothems, but geologists have started making interesting discoveries by studying the magnetic properties of the sediments. This speleothem is formed of aragonite, an alternative crystal form of calcium carbonate (limestone), that forms only under dry conditions.

Speleothems can be formed from a variety of minerals: ice, for example.

Though it looks exactly like ice, this is the mineral epsomite.

Many of the most well known speleothems, like these stalactites, are formed of the mineral calcite, which is the crystal form of calcium carbonate that forms under wet conditions.

These delicate hairlike forms are made of calcium sulfate, commonly known as gypsum, that extrude directly from the mud in the cave walls because of the differing moisture levels in the cave mud and the cave air.

Gypsum also forms "flowers".

Different speleothem shapes are usually caused by differing surface conditions, which, in turn cause different rates of water movement through roof cracks and differing rates of dissolving and reforming of the mineral crystals.

Sometimes differing "micro climate" within the same room can cause differing types of speleothems to form very close to one another.

Sometimes cave pools maintain the same level for so long, with continuously refreshed mineral content, that they form large crust speleothems at the edges of the pool.

Some speleothems are awe inspiring because of their large size, like this 100 foot tall column formation,

while others achieve the same effect with their delicate beauty,

while still others achieve it by their shape alone.

	These scallop shapes carved by the acidic spring floodwaters are an example of a speleogen formation.		Here are some speleogens (the ceiling channels and cracks) covered with speleothems (stalactites, stalagmites, and columns).
	Helictites are basically tiny stalactites that grow so slowly they are able to ignore gravity.		Helictites can take on many colors and shapes.

These incredible formations are from a place called Silent Splendor.

For more great formation photos, see Dave Bunnell's photos on the Virtual Cave web site.

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Page Maintained by: and Morrie Gasser