Aragonite is usually transparent or translucent, and colorless or white when pure. Impurities may cause shades of yellow, blue, pink, or green to occur, It is found in many different habits: small, elongate, prismatic crystals form in radiating groups, and concretions and stalactites are also common. It has poor cleavage.

Found mainly in sedimentary environments, aragonite may form as tufa (porous rock) in Czechoslovakia and Turkey. Other localities include Spain, Colorado (USA), France, and (Cambria (England).

Almost all aquamarine in the market has been heat-treated to enhance its color. Care must be taken not to overheat the stones, as they may become colorless.