Speleothem

speleothem: A secondary mineral deposited in a cave by the action of water. Also known as cave formation.
From: Sybil P. Parker ed. (1997): McGraw-Hill Dictionary of Geology and Mineralogy, 380 pages, McGraw-Hill; ISBN: 0070524327 amazon.com

The most common speleothems consist of calcite (CaCO₃), aragonite (CaCO₃) or gypsum (CaSO₄). Some common types are:

• Boxwork: Thin plates of calcite forming boxes.
• Cave Coral: very small short stalks with bulbous ends, usually occurring in numbers in patches.
• Cave Pearl: a smooth, polished and rounded speleothem found in shallow hollows into which water drips.
• Column, Pillar: a speleothem from floor to ceiling, formed by the growth of a stalactite and a stalagmite, or by the growth of either to meet bedrock.
• Curtain, Shawl, Bacon Rind: a speleothem in the form of a wavy or folded sheet hanging from the roof or wall of a cave, often translucent and resonant.
• Diadochite: speleothems looking like stalactites and stalagmite, found in mines, growing extremely fast.
• Dogtooth Spar: huge calcite cristals forming crusts on floor and walls, formed in standing water.
• Helictite, Eccentric: a speleothem of abnormal shape or attitude.
• Moonmilk, Rockmilk: a soft, white plastic mineral consisting of Calcite, hydrocalcite, hydromagnesite or huntite.
• Pendulite: resembling a pendulum, a stalactite becoming thicker at the bottom.
• Pillar: a dripstone where the stalactite- and stalagmite-part are grown together.
• Rimstone Pool: pools with very thin calcite rims.
• Shield: a calcite conretion in the form of a thin disc, a circuar plate forming at the wall.
• Stalactite: a dripstone hanging downwards from a roof or wall, of cylindrical or conical form, usually with a central hollow tube.
• Stalagmite: a dripstone projecting vertically upwards from a cave floor and formed by precipitation from drips.
• Palm Trunk Stalagmites: a stalagmite where the shape is reminiscent either of a palm trunk, or of a stack of plates.
• Stegamite
• Straw: a long, thin-walled tubular stalactite less than about 1 cm in diameter.
• Vermiculation

• See also
• The Virtual Cave
• Speleothems