Maghemite

Maghemite (Fe2O3, γ-Fe2O3) is a member of the family of iron oxides. It has the same structure as magnetite, that is, it is spinel ferrite and is also ferrimagnetic. Maghemite can be considered as an Fe(II)-deficient magnetite with formula where represents a vacancy, indicates tetrahedral positioning and octahedral.
See more at Wikipedia.org...

General Information:
 Chemical Formula:
gamma-Fe+++2O3
 Composition:
(Molecular Weight = 159.69 gm)
Iron 69.94 % Fe
Oxygen 30.06 % O 
 Empirical Formula:
Fe3+2O3
 Locality:
Iron mountain mine, 9.5 miles NW of Redding, Shasta Co., California.
Physical Properties:
 Cleavage:
None
 Color:
dark brown.
 Density:
4.9
 Diaphaniety:
Opaque
 Habits:
Massive - Uniformly indistinguishable crystals forming large masses., Massive - Granular - Common texture observed in granite and other igneous rock.,
 Hardness:
6 - Orthoclase
 Luster:
Metallic
 Streak:
brown
More details...