Paraumbite

General Information: Chemical Formula:K3Zr2HSi6O18·n(H2O) n=3 to 7 Composition:(Molecular Weight = 811.30 gm)Potassium 14.46 % K Zirconium 22.49 % ZrSilicon 20.77 % SiHydrogen 0.87 % H Oxygen 41.41 % O  Empirical Formula: K3Zr2HSi6O18·3(H2O) Environment:Alkalic pegmatites. Locality:Mt. Eveslogchorr, eastern Khibiny massif, Kola Peninsula, Russia. Name Origin:Named for the close structural similarity to umbite.Physical Properties: Cleavage:[010] Perfect, [100] Good Color:colorless, white, or light yellow. Density:2.59 Diaphaniety:Transparent to Translucent Habits:Pseudo Hexagonal - Crystals show a hexagonal outline., , Hardness:4.5 - Between Fluorite and Apatite Luster:Vitreous - Pearly Streak:whiteMore details...