Calcite facts for kids

Calcite

The unit cell of calcite

Calcite is a very common mineral found all over Earth. It's a main part of many rocks, especially limestone and marble. You can also find it in caves, forming cool shapes like stalactites and stalagmites.

Calcite is a type of calcium carbonate, which means it's made of calcium, carbon, and oxygen. Its chemical formula is CaCO₃. It belongs to a group of minerals called carbonate minerals.

Where Calcite is Found

Calcite is one of the most common minerals on our planet. It makes up a big part of sedimentary rocks, especially limestone. It's also the main mineral in metamorphic marble.

You can find calcite in veins where hot water has flowed through rocks. It also forms amazing structures in caverns, like stalactites (which hang from the ceiling) and stalagmites (which grow up from the floor).

Calcite in Living Things

Many sea creatures use calcite to build their shells and hard parts. This includes tiny plankton and the hard parts of red algae. Some sponges, brachiopods, and echinoderms also use calcite. Most bryozoa and parts of some bivalves, like oysters, are made of calcite.

Ancient Eyes of Calcite

Trilobites were ancient sea creatures that lived a very long time ago. They became extinct about 250 million years ago. These amazing creatures had special compound eyes. Their eyes used clear calcite crystals to form the lenses, helping them see underwater.

Images for kids

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  Crystal structure of calcite

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  Demonstration of birefringence in calcite, using 445 nm laser

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  One of several calcite or alabaster perfume jars from the tomb of Tutankhamun, d. 1323 BC

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  Calcite with mottramite

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  Trilobite eyes employed calcite

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  Calcite crystals inside a test of the cystoid Echinosphaerites aurantium (Middle Ordovician, northeastern Estonia)

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  Rhombohedrons of calcite that appear almost as books of petals, piled up 3-dimensionally on the matrix

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  Calcite crystal canted at an angle, with little balls of hematite and crystals of chalcopyrite both on its surface and included just inside the surface of the crystal

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  Thin section of calcite crystals inside a recrystallized bivalve shell in a biopelsparite

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  Grainstone with calcite ooids and sparry calcite cement; Carmel Formation, Middle Jurassic, of southern Utah, USA.

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  Several well formed milky white casts, made up of many small sharp calcite crystals, from the sulfur mines at Agrigento, Sicily

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  Reddish rhombohedral calcite crystals from China. Its red color is due to the presence of iron

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  Cobaltoan, the cobalt-rich variety of calcite

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  Sand calcites (calcites heavily included with desert sand) in South Dakota, USA

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  Calcite, butterfly twin, 4,0 × 3,3 × 1,6 cm. José María Patoni, San Juan del Río, Durango (Mexico)

See also

In Spanish: Calcita para niños