sedimentary

Weathered iron-rich sandstone or ironstone concretion

Ferruginous sandstone; chiefly quartz (SiO₂) cemented by iron oxides such as hematite (Fe₂O₃) and goethite (FeO(OH))

AI-generated identification · may be incorrect

Hardness about 5–7; ochre-orange to brown, earthy to dull luster, granular and layered texture, with no obvious cleavage. The rounded, strongly weathered form and rusty coloration suggest an ironstone concretion or ferruginous sandstone rather than a crystal mineral.

Identified September 9, 2026More sedimentary →

Explore Weathered iron-rich sandstone or ironstone concretion in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

At a glance

Common name: Weathered iron-rich sandstone or ironstone concretion
Scientific name: Ferruginous sandstone; chiefly quartz (SiO₂) cemented by iron oxides such as hematite (Fe₂O₃) and goethite (FeO(OH))
Category: sedimentary
Identified: September 9, 2026
Method: Standard

AI Estimated Value

Typically $5–$25 for a common hand specimen; unusually patterned or locality-documented pieces may sell for $30–$100.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

Formed when silica-rich sand was deposited and later cemented by iron oxides in an oxidizing groundwater environment; subsequent erosion rounded the specimen. Its precise age cannot be determined from the image and may range from Paleozoic to Cenozoic depending on locality.

Uses & applications

Usually collected as a geological specimen or used as durable decorative stone; iron-rich sandstone has historically been quarried for building stone and, locally, iron ore.

Geological facts

Iron oxides produce the characteristic yellow, orange, red, and brown colors. Concentric or wavy bands may reflect changing groundwater chemistry during concretion growth.

Field identification & locations

Common in arid, coastal, and sedimentary terrains worldwide, including Australia, India, Africa, and the western United States. A streak test may show yellow-brown to reddish powder; it should feel dense and resist scratching by a steel knife.