FeO(OH)Orthorhombic
Goethite
FeO(OH)
OxidesChemical FormulaFeO(OH)
Crystal SystemOrthorhombic
Mohs Hardness5.5
Specific Gravity4.27
ColorBrownish black to yellowish brown
LusterAdamantine to dull
StreakBrownish yellow
CleavageOne direction
FractureUneven
Occurrence
Common weathering product of iron-bearing minerals. Main component of rust.