# calcite

/ˈkæɫˌsaɪt/ (US) · /kˈælsaɪt/ (UK) · CEFR C1 · Noun

Source: https://englishreference.com/word/calcite
Updated: 2026-10-18

## Definition

a common mineral made of calcium carbonate, found in limestone, marble, and chalk. You often see it as white or clear crystals that break easily.

For teachers: a crystalline form of calcium carbonate forming the main component of limestone, marble, and chalk. Relatively soft and rhombohedral in structure, dissolving readily in dilute acid with effervescence.

## Examples

- Limestone contains a lot of calcite.
- The students test the white crystals with acid to confirm the mineral is calcite.
- Under polarized light, thin sections of marble reveal interlocking calcite grains whose twinkling extinction patterns record ancient tectonic stress.

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