Reyerite

General Information: Chemical Formula:(Na,K)4Ca14Si22Al2O58(OH)8·6(H2O) Composition:(Molecular Weight = 2,513.12 gm)Potassium 1.56 % K Sodium 2.74 % NaCalcium 22.33 % CaAluminum 2.15 % AlSilicon 24.59 % SiHydrogen 0.80 % H Oxygen 45.84 % O  Empirical Formula: Na3KCa14Si22Al2O58(OH)8·6(H2O) Environment:In cavites in basalt and basic tuffs. Locality:Niaqornat, Nuussuaq, Greenland. Name Origin:Named for Eduard Reyer (1849-1907), Austrian geologist.Physical Properties: Cleavage:[0001] Perfect Color:colorless, white, or light green. Density:2.54 - 2.578, Average = 2.55 Diaphaniety:Transparent to Translucent Habits:Massive - Uniformly indistinguishable crystals forming large masses., Spherical - Spherical, rounded aggregates., Micaceous - Platy texture with "flexible" plates. Hardness:3-4 - Calcite-Fluorite Luster:Vitreous - Pearly Streak:whiteMore details...

(Na,K)Ca14(Si,Al)24O58(OH)8 6(H2O)