Carbonate mineral
A mineral whose structure contains carbonate ions (CO₃²⁻) as a principal component, commonly combined with calcium, magnesium, iron, or other cations.
Carbonate: A polyatomic ion, CO₃²⁻, consisting of one carbon atom bonded to three oxygen atoms. This ion is the defining structural component shared by carbonate minerals.
Calcite: A calcium carbonate mineral, CaCO₃, that crystallizes in the trigonal system. It is the most widespread carbonate mineral and a common reference for the family.
Carbonate equilibrium: The linked chemical equilibria among dissolved carbon dioxide, carbonic acid, bicarbonate, and carbonate ions in water. These equilibria govern when carbonate ions are available to form or dissolve minerals.
Limestone: A sedimentary rock composed mainly of calcium carbonate minerals, especially calcite. Calcite-rich limestone is quarried for construction, cement, and industrial feedstock.
Carbon cycle: The movement of carbon among the atmosphere, oceans, living organisms, soils, and rocks. Carbonate formation stores carbon in long-lived sedimentary minerals.
Crystal structure: The ordered arrangement of atoms, ions, or molecules in a crystalline solid. Carbonate minerals differ in how carbonate groups and metal cations pack into repeating structures.
Aragonite: An orthorhombic polymorph of calcium carbonate, CaCO₃. Its distinct structure demonstrates that one carbonate composition can form different minerals.
Mineral precipitation: The formation of solid mineral phases from a fluid when dissolved components become supersaturated. Supersaturated waters can deposit carbonate minerals as crystals or sediment.
Cement: A binding material that hardens through chemical reactions with water and joins aggregates in concrete and mortar. Limestone-derived carbonate minerals supply much of the raw material for Portland cement.
Carbonate sedimentation: The accumulation and burial of carbonate particles or precipitates in sedimentary environments. It turns mineral production into extensive carbonate rock records.