Chemical Formula: (K,Na)(Fe+++,Al,Mg)2(Si,Al)4O10(OH)2
Help on Composition: Composition: Molecular Weight = 426.93 g
 
Hydrogen 0.47 % H 4.22 % H2O 0.00 %
Oxygen 44.97 % O 0.00 % 0.00 %
Sodium 0.27 % Na 0.36 % Na2O 0.00 %
Magnesium 2.28 % Mg 3.78 % MgO 0.00 %
Aluminum 1.90 % Al 3.58 % Al2O3 0.00 %
Silicon 25.00 % Si 53.48 % SiO2 0.00 %
Potassium 5.49 % K 6.62 % K2O 0.00 %
Iron 19.62 % Fe 3.37 % FeO 24.31 % Fe2O3



100.00 % 75.41 % 24.31 %
 
Help on Empirical Formula: Empirical Formula: K0.6Na0.05Fe3+1.3Mg0.4Fe2+0.2Al0.3Si3.8O10 (OH)2
Help on Environment: Environment: Altered from detrital biotite by marine diagenesis in shallow water under reducing conditions; especially in sandstone
Help on Locality: Locality: Otago Peninsula, New Zealand. Common world wide.. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: From the Greek "glaucos" for the blue green color
Help on Synonym: Synonym: