Baryte
A small number of organisms selectively mineralize baryte (BaSO 4) (Fig. 6).Baryte is a denser mineral (BaSO 4 = 4.5 g/cm 3) than either celestite (SrSO 4 = 3.96 g/cm 3) or calcite (CaCO 3 = ∼2.8 g/cm 3).This high mass density favors the use of baryte in gravity-sensing statoliths (∼1 μm in diameter) found in vacuoles in some freshwater green algae …
