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 % Na
Calcium 22.33 % Ca
Aluminum 2.15 % Al
Silicon 24.59 % Si
Hydrogen 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:
white
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