Mineral Class 05: Carbonates and Nitrates

Rhodochrosite on (scepter)quartz from Cavnic (Kapnic; Kapnik), Maramures, Romania
Carbonate mineral, any member of a family of minerals that contain the carbonate ion, CO3, as the basic structural and compositional unit.
The carbonates are among the most widely distributed minerals in the Earth’s crust; generally the carbonate minerals are found at or near the surface.
They represent the Earth's largest storehouse of carbon.