sedimentary

Sandstone (Ferruginous)

Arenite (Fe-rich)

Hardness: 6-7 (Mohs scale); Color: Brown, reddish-tan, earthy ochre due to iron oxide; Luster: Dull/Earthy; Structure: Clastic, fine-to-medium grained sand particles; Cleavage: None/Irregular fracture.

Hardness: 6-7 (Mohs scale)
Color: Brown, reddish-tan, earthy ochre due to iron oxide
Luster: Dull/Earthy

Identified April 10, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the accumulation and cementation of mineral particles or rock fragments, specifically quartz and feldspar, in high-energy environments like riverbeds or coastal zones. The presence of iron oxides (like hematite or goethite) provides the reddish-brown staining.

Uses & applications

Commonly used as a building material, in the manufacture of glass (if high silica), or crushed for use in road construction and paving.

Geological facts

Sandstone makes up about 20% of all sedimentary rocks on Earth. The famous 'Red Rocks' in Colorado are composed of iron-rich sandstone similar to this specimen.

Field identification & locations

Identify in the field by its 'sandpaper' texture and visible grain layers. It is ubiquitous in sedimentary basins worldwide. For collectors, look for cross-bedding or ripple marks indicating ancient water flow.