sedimentary
Ironstone (Limonitic/Hematitic Sandstone)
Ferruginous sandstone (predominantly Fe2O3 and FeO(OH))
Hardness: 5-6 (variable), Color: Dark brown to reddish-orange, Luster: Dull/Earthy, Structure: Granular or concretionary, heavy for its size due to iron content.
Identified More sedimentary →
Explore Ironstone (Limonitic/Hematitic Sandstone) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 5-6 (variable), Color: Dark brown to reddish-orange, Luster: Dull/Earthy, Structure: Granular or concretionary, heavy for its size due to iron content.
Formation & geological history
Formed through the chemical precipitation of iron oxides within sedimentary layers, or as a residual deposit from the weathering of other iron-rich rocks. Common in terrestrial and shallow marine environments.
Uses & applications
A historic source of iron ore; currently used as a decorative stone, in construction as road metal, and for landscaping.
Geological facts
Ironstone concretions can sometimes form 'rattle stones' where a loose core creates sound. Famous deposits provided the raw material for the Industrial Revolution in regions like the English Midlands.
Field identification & locations
Identify by its characteristic rusty red-brown streak, high density, and localized staining of surrounding soil. Frequently found in riverbeds and eroded hillsides.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Cone-in-cone structure (Limestone)
Cone-in-cone structure (Secondary Sedimentary Structure)
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary