sedimentary

Weathered sandstone cobble

Quartz-rich sandstone, chiefly SiO₂ with clay/iron-oxide cement

AI-generated identification · may be incorrect

Typically Mohs hardness 6–7 for quartz grains, but weaker where cement is soft; tan, pink, and gray, with dull to slightly gritty luster. The specimen appears rounded and heavily weathered, with possible bedding or mineral staining.

Identified August 16, 2026More sedimentary →

Explore Weathered sandstone cobble 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 sandstone cobble
Scientific name: Quartz-rich sandstone, chiefly SiO₂ with clay/iron-oxide cement
Category: sedimentary
Identified: August 16, 2026
Method: Standard

AI Estimated Value

About $1–$10 as a common natural cobble; potentially $10–$30 if unusually shaped or attractive, but provenance and confirmed composition would be needed for higher value.

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 sand accumulated, compacted, and cemented in an ancient river, beach, dune, or shallow-marine setting; its exact geological age cannot be determined from the image. Later stream transport produced the smooth cobble shape.

Uses & applications

Used as building stone, paving, aggregate, landscaping material, and occasionally as a decorative or carving stone; this weathered piece has little commercial value.

Geological facts

Sandstone color commonly reflects iron oxides (red/yellow) or feldspar and clay minerals (pink/gray). Rounded cobbles indicate substantial transport and abrasion in flowing water.

Field identification & locations

Identify it by visible sand-sized grains, gritty texture, rounded stream-worn form, and lack of distinct crystalline cleavage; a streak or fresh broken surface helps distinguish it from quartzite. Common in riverbeds and gravel deposits worldwide.