A hydrous phosphate of calcium, sodium, and potassium; hexagonal; crystalline crusts and minute crystals; grayish- to greenish-white. The mineral from Dehrn, Nassau, Germany, is richer in sodium, conforming nearly to the formula 7CaO.Na₂O.2P₂O₅.H₂O , whereas the mineral found near Fairfield, UT is described as 14CaO.2(Na,K)₂O.4P₂O₅3(H₂O,CO₂) .