Calcite (Inventory)

From LagWiki

Revision as of 01:37, 19 April 2011

Flowstone

Stalactite

deflected

soda straw

Soda straws

Stalagmite

Column

Popcorn

Button popcorn

Bell Canopy

Boxwork

Boxwork. Other formations visible include popcorn and dogtooth spar.

The Boxwork inventory field should be used to list stations which exhibit boxwork. Boxwork is not technically a speleothem but a speleogen. That is, it is not a formation but a residual of dissolution. Boxwork forms when cracks in the bedrock are filled with a mineral which is harder to dissolve than the bedrock itself. When the bedrock dissolves, it leaves the mineral which used to fill the cracks exposed. It often appears on the ceiling but may be present anywhere bedrock is exposed. It may be obscured by secondary formations. Boxwork can appear as small examples or large areas. It often takes on polygonal shapes (usually rectangular) but may be almost any shape. It need not project far from the rock to be considered boxwork. Often it is a different color than the bedrock (usually darker).

Although the field appears in the calcite section of the CCNP Cave Inventory Form, any boxwork no matter its specific mineral content (which may be difficult to identify anyway and is often not calcite) should be listed.

Calcite Coating

Calcite coating on bedrock. The arrow identifies a sponge.

A calcite coating is a thin layer of calcite usually over bedrock or breakdown. It is much thinner than a calcite crust.

It is sometimes difficult to differentiate between a calcite coating, an aragonite coating, a gypsum coating, and even moonmilk.

Calcite tends to have square-ish crystals. Gypsum sometimes makes starbursts. Aragonite and moonmilk are both bright white. Aragonite coatings are not an inventory item on the CCNP Cave Inventory Form and should be inventoried as a calcite coating, so there is no need to distinguish between these two.

Sometimes it is difficult to positively differentiate between different coatings in the field without destructive testing.

See also

• Gypsum Coating
• Moonmilk

Calcite Crust

Coral Pipes

Coral Stalagmite

Conulite

Drapery

Drip Pit Lining

Folia

Helictite

antler

beaded

snake dancer

subaqueous

other

Mammillary

Pearl

Typical nest of cave pearls

Cave pearls are small balls of calcite or aragonite that usually form on the floor in shallow pools or depressions. They are formed from constant, steady dripping action causing agitation of a small seed crystal building up layers of calcite. They can occur singularly in depressions in the bedrock but are usually found in nests. Some of the pearls may become cemented into the floor. Cave pearls need not always be round. Sometimes they can have a cylindrical shape. The size varies from very small but rarely gets much larger than a golf ball or small egg. Most are pea to marble sized. Nests of pearls can easily be obscured by mud or silt. Great care should be taken not to disturb them during a survey.

Cave pearls are not to be confused with pisolites.

See also

• Pisolites

References

• Palmer, Arthur N. (2007) Cave Geology CAVE BOOKS, Dayton, OH p 280 ISBN-13: 978-0-939748-66-2, ISBN-10: 0-939748-66-5

Pool Finger

Raft

Raft Cone

Rim

Rimstone Dam

Shelfstone

Spar

dogtooth

Dogtooth spar

The dogtooth field should be used to list stations which exhibit dogtooth spar crystals.

Dogtooth spar is a crystaline speleothem usually of calcite. The shape is scalenohedral -- triangular faces. The size can vary from barely discernable to quite large. The color can vary too. Often only one end of the scalenohedron may be visible giving each crystal a pyramid-like shape. Sometimes, both ends of the crystal can be seen forming a kind of faceted football shape. They can occur singularly or in clusters. They can often be found lining the insides of vugs or cavities and cracks but can also occur on the ceiling or walls directly. Since they formed when the cave was phreatic, they can be obscured by other formations such as flowstone, popcorn, crusts or staining. When looking for dogtooth spar, take the time to look into cracks and vugs in the walls, floor and ceiling. And don't forget to examine breakdown -- it may possess a vug containing dogtooth spar. Often when dogtooth spar is found, it can be found at nearby stations, too.

Gallery

Larger dogtooth spar crystals partially obscured by flowstone, popcorn and staining

nailhead

Nailhead spar

The nailhead field should be used to list stations which exhibit nailhead spar.

Nailhead spar typically is "flatter" or more "cubic" than dogtooth spar. The shape is a rhombohedron where each facet is a rhombus. Except for the shape of each crystal (which is really just one of the two primary crystaline shapes of calcite) it has characteristics very similar to dogtooth spar and can be found in similar locations.

They can occur singularly; but are usually found in clusters. They can be found lining the insides of vugs or cavities and cracks but can also occur on the ceiling or walls directly. They formed when the cave was phreatic and can be obscured by other formations such as flowstone, popcorn, crusts or staining. When looking for nailhead spar, take the time to look into cracks and vugs in the walls, floor and ceiling. And don't forget to examine breakdown -- it may possess a vug containing nailhead spar.

chenille/pool

The chenille/pool field should be used to list stations which have pool spar crystals.

Pool spar are well-defined crystals that grew under water. Chenille spar are a subset of pool spar with small spar crystals coating the pool or shelfstone that are almost velvety.

The pool may be dry or still filled with water.

External links

• Pool Spar webpage Black Chasm CA
• Pool spar webpage at the Virtual cave

Shield

Splash Ring

Splash Ring.

Tray