# Calcium carbonate, CaCO3

Calcium carbonate (CaCO3) is a common inorganic compound that exists in various forms, including calcite, aragonite, and vaterite, each with distinct crystal structures and properties. Calcite, the most stable form, is a birefringent material widely studied for its unique optical characteristics. Its birefringence enables the separation of light into two refracted rays, making it useful in polarizers, optical modulators, and other specialized optical applications. Beyond optics, calcium carbonate is a key component in the construction industry, where it is used as a building material and in the manufacture of cement. It also serves as a primary raw material in the production of lime (CaO) and finds widespread use as a filler in products like paper, paint, and plastics. In biological contexts, calcium carbonate is the main component of shells, coral skeletons, and eggshells. It is synthesized through various methods, including precipitation from calcium and carbonate ions in aqueous solutions, and its properties can be fine-tuned through doping or composite formation. Overall, calcium carbonate is a multifaceted material with applications ranging from optics and construction to biology.

## Other names

- Calcium(II) carbonate
- Limestone
- Aragonite
- Chalk
- Marble
- Pearl
- Oyster

## Mineral

- Calcite

## External links

- Calcium carbonate - Wikipedia
- Calcium carbonate - WebElements
- Calcite - Wikipedia