Ettringite

General Information: Chemical Formula:Ca6Al2(SO4)3(OH)12·26(H2O) Composition:(Molecular Weight = 1,255.11 gm)Calcium 19.16 % CaAluminum 4.30 % AlHydrogen 5.14 % H Sulfur 7.66 % S Oxygen 63.74 % O  Empirical Formula: Ca6Al2(SO4)3(OH)12·26(H2O) IMA Status:Approved IMA 1960Physical Properties: Cleavage:[1010] Perfect Color:colorless or white. Density:1.8 Diaphaniety:Transparent Habits:Acicular - Occurs as needle-like crystals., , Hardness:2-2.5 - Gypsum-Finger Nail Luminescence:Non-fluorescent. Luster:Vitreous (Glassy) Streak:whiteMore details...

Ca6Al2(SO4)3(OH)12 26(H2O)