sedimentary

Ferruginous Sandstone Pebble

Iron-rich Clastic Sedimentary Rock

AI-generated identification · may be incorrect

Hardness: 6-7 (Mohs scale); Color: Dark brown to reddish-brown; Luster: Dull to earthy; Texture: Fine-grained, gritty feel; Shape: Water-worn/rounded.

Hardness: 6-7 (Mohs scale)
Color: Dark brown to reddish-brown
Luster: Dull to earthy

Identified July 9, 2026More sedimentary →

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Physical properties

Hardness: 6-7 (Mohs scale); Color: Dark brown to reddish-brown; Luster: Dull to earthy; Texture: Fine-grained, gritty feel; Shape: Water-worn/rounded.

Formation & geological history

Formed through the lithification of sand grains bound by iron-oxide cement (such as hematite or goethite). These stones are common in coastal and river environments where water action rounds the fragments over centuries.

Uses & applications

Commonly used for landscaping, road base, and construction aggregate when crushed. Small rounded pebbles are popular for decorative garden paths or aquarium substrate.

Geological facts

The reddish-brown streak visible on the stone is often caused by the oxidation of iron minerals within the rock, essentially a form of natural 'rusting' that cements the sand grains together.

Field identification & locations

Look for a gritty texture and a heavy feel relative to size due to iron content. Found commonly on beaches and in stream beds. Collectors often look for examples with unique weathering patterns.