General Information:
Chemical Formula:
(Fe++,Mg)4(Fe+++,V+++)2[Si6O15](O,OH)8
Composition:
(Molecular Weight = 861.42 gm)
Magnesium 1.41 % Mg
Vanadium 2.96 % V
Iron 32.42 % Fe
Silicon 19.56 % Si
Hydrogen 0.94 % H
Oxygen 42.72 % O
Empirical Formula:
Fe2+3.5Mg0.5Fe3+1.5V3+0.5Si6O15OH8
IMA Status:
Approved IMA 1985
Locality:
Harhada iron deposit, near the Jining-Erlian railway, Inner Mongolia, China.
Name Origin:
Named for the locality.
Physical Properties:
Cleavage:
[001] Perfect, [100] Perfect
Color:
black.
Density:
3.11
Diaphaniety:
Nearly opaque
Habits:
Fibrous - Crystals made up of fibers., Platy - Sheet forms (e.g. micas)., Aggregates - Made of numerous individual crystals or clusters.
Hardness:
3.5 - Copper Penny
Luster:
Silky
Streak:
brown
More details...