Whewellite is a calcium oxalate mineral, and as such belongs in the organic minerals classification. Whewellite is one of two calcium oxalate minerals (the other being weddellite) found in soils. It commonly occurs in forest soils where oxalic acid exuded from roots or ectorrhizae combines with free Ca in the soil to produce calcium oxalate.
Highlighting FeaturesCalcium (Ca) atoms Oxalate polyanions A single oxalate polyanion Single unit cell All atoms
Occurs mainly in soils as a secondary mineral formed by the complexation of free Ca by oxalic acid released from roots and mycorrhizae.
Tazzoli, V., and C. Domeneghetti. 1980. The crystal structures of whewellite and weddellite: re-examination and comparison. American Mineralogist 65:327-334