Limonite with Goethite and Quartz
Goethite-Limonite pseudomorph / mixture · Mineral Specimen / Iron Ore
Crystal System
Orthorhombic (Goethite), Amorphous (Limonite), Trigonal (Quartz inclusions); massive to earthy habit.
Mineral Group
Oxides / Hydroxides
Chemical Formula
FeO(OH)·nH2O (Limonite), α-Fe3+O(OH) (Goethite), SiO2 (Quartz)
Formation Process
Secondary formation through the weathering of iron-rich minerals (metasomatic or sedimentary chemical precipitation).
About This Crystal
An earthy, yellowish-brown to dark brown ochreous mass. It features a dull to sub-metallic luster with localized crystalline vugs and white quartz inclusions.
Physical Characteristics
Color: Yellowish-brown to dark rusty-brown. Streak: Yellowish-brown. Cleavage: Indistinct. Fracture: Uneven to conchoidal. Specific Gravity: 2.7–4.3. Non-magnetic. Brittle.
Optical Properties
Generally opaque; small quartz inclusions may be transparent. Low refractive index for the earthy matrix; non-pleochroic in massive form.
Hardness & Durability
Origin Region
Worldwide; notable sources include Germany, USA (Arizona), Brazil; forms in gossans and weather zones.
Hardness & Durability
Mohs hardness 4–5.5. Brittle toughness. Generally stable but can be porous and susceptible to staining or physical crumbling.
Care & Maintenance
Avoid acidic cleaners. Clean with dry or slightly damp soft cloth. Store in a dry environment to prevent further oxidation or crumbling.
Rarity & Value
Common. Low monetary value; primarily of interest as a geological specimen or coloring pigment (ochre).
Special Characteristics
Pseudomorphism (often replacing pyrite) and its use as a natural earth pigment known as ochre.
Lore & History
Historically used as one of the first pigments for cave paintings. In lore, it is associated with grounding, physical stamina, and the base chakra.