Goethite

Geothite is named for the German poet Goethe. It forms as a secondary mineral by the oxidation of iron minerals or as a precipitate in swamps and bogs. It is a widespread mineral, found in quantity all over the world. Although is it not as rich as hematite, it is still an important ore of iron.

Chemical Formula:

FeO(OH)

Mineral Class:

Hydroxide

Crystal System:

Orthorhombic

Symmetry:

2/m 2/m 2/m

Hardness:

5-5.5

Specific Gravity:

4.37

Cleavage:

{010} perfect

Fracture:

Hackly

Color:

Shades of yellow/brown

Streak:

Yellow-brown

Luster:

Adamantine, dull, silky

Transparency:

Sub-translucent

Common Habits:

Acicular, radial

Other Properties:

Notable Localities:

Alsace, France; Westphalia, Germany; Bohemia, Czech Republic; Cornwall, England

Uses:

Ore of iron

Associated Minerals:

Iron, quartz, microcline

Specimens:


Goethite
Birmingham, AL


Goethite
Lake George, CO