Taranakite

General Information: Chemical Formula:K3Al5(HPO4)6(PO4)2·18(H2O) Composition:(Molecular Weight = 1,342.30 gm)Potassium 8.74 % K Aluminum 10.05 % AlPhosphorus 18.46 % P Hydrogen 3.15 % H Oxygen 59.60 % O  Empirical Formula: K3Al5(HPO4)6(PO4)2·18(H2O)Physical Properties: Color:gray white, yellowish white, or white. Density:2.09 Hardness:1-2 - Between Talc and Gypsum Luminescence:Fluorescent. Streak:whiteMore details...

(K,NH4)Al3(PO4)3(OH) 9(H2O)