Lepidocrocite

Physical properties

Habit: scaly, fibrous, blady, tabular, pulverulent.
Color: red, yellowish brown, or blackish brown.
Luster: submetallic.
Diaphaneity: opaque.
Streak: dark yellow brown, or orange.
Cleavage: perfect (010), good (001).
Fracture: uneven.
Occurrence: iron ore deposits.

Structure and conformation

γ-FeOOH, lepidocrocite [12022-37-6], has a boehmite structure with color changes from yellow to orange with increasing particle size.