Goethite
Image: <a href="//commons.wikimedia.org/wiki/User:Islam90" title="User:Islam90">Islam90</a> (CC BY-SA 4.0)
Mineral NameGoethite
Chemical FormulaFeO(OH)
Mohs Hardness5
Crystal Systemorthorhombic
Lusteradamantine
Streak Coloryellowish-brown
Cleavageperfect on {010}, poor on {100} and {001}
Fractureuneven
Specific Gravity3.3
Colorsyellow, brown, reddish-brown, blackish-brown
Transparencyopaque
Type LocalitySiegen, Germany
Mineral GroupOxides
Usesiron ore, pigment, collector
Associated Mineralshematite, limonite, quartz, calcite
Raritycommon
Description
This microscopic image displays Goethite with a distinct botryoidal or mammillary texture, appearing in shades of greyish-brown under normal light.
Geological Context
Goethite is a common secondary mineral formed by the weathering of iron-rich minerals, often found in gossans, bogs, and as a major component of lateritic soils and limonite deposits.
