General Information:
Chemical Formula:(Na,K)(Fe+++,Fe++)3(Fe,Mg,Al)6(BO3)3Si6O18(OH)4
Composition:(Molecular Weight = 1,332.93 gm)Potassium 0.73 %
K Sodium 1.29 %
NaMagnesium 3.28 %
MgAluminum 1.21 %
AlIron 27.65 %
FeSilicon 12.64 %
SiBoron 4.87 %
B Hydrogen 0.30 %
H Oxygen 48.01 %
O Empirical Formula: Na0.75K0.25Fe3+2.25Fe2+0.75Fe2+3.6Mg1.8Al0.6(BO3)3(Si6O
IMA Status:Approved IMA
Physical Properties: Cleavage:None
Color:black.
Density:3.26
Diaphaniety:Translucent
Hardness:7 - Quartz
Luster:Resinous
Streak:brown
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