Overview

Calcium carbonate (KAL-see-um CAR-bun-ate) is one of the most common compounds on Earth, making up about 7 percent of Earth's crust. It occurs in a number of minerals and other natural materials, including aragonite, calcite, chalk, limestone, marble, marl, oyster shells, pearls, and travertine. Stalactites and stalagmites found in caves are made primarily of calcium carbonate. As indicated by the melting points of aragonite and calcite, the compound's physical properties may differ somewhat depending on its crystal form. It typically occurs as an odorless, tasteless white powder or colorless crystals.

Key Facts

Other Names:

Limestone; chalk; aragonite; calcite

Formula:

CaCO₃

Elements:

Calcium, carbon, oxygen

Compound Type:

Inorganic salt

State:

Solid

Molecular Weight:

100.09 g/mol

Melting Point:

Calcite: 1330°C (2430°F); aragonite: decomposes at about 825°C (1520°F)

Boiling Point:

Not applicable

Solubility:

Very slightly soluble in water; soluble in dilute acids; insoluble in organic solvents

How It Is Made