sedimentary

Weathered sandstone or siltstone cobble

Clastic sedimentary rock, likely quartz–feldspar lithic sandstone (exact identification requires testing)

AI-generated identification · may be incorrect

Tan-brown, dull to earthy luster, fine- to medium-grained and apparently massive; hardness roughly 5–7 if quartz-rich, with no obvious cleavage. Specific gravity is typically about 2.2–2.7.

Identified September 7, 2026More sedimentary →

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At a glance

Common name: Weathered sandstone or siltstone cobble
Scientific name: Clastic sedimentary rock, likely quartz–feldspar lithic sandstone (exact identification requires testing)
Category: sedimentary
Identified: September 7, 2026
Method: Standard

AI Estimated Value

About $1–$10 as an ordinary specimen; more if it proves to be a distinctive fossiliferous or attractive building stone.

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

Tan-brown, dull to earthy luster, fine- to medium-grained and apparently massive; hardness roughly 5–7 if quartz-rich, with no obvious cleavage. Specific gravity is typically about 2.2–2.7.

Formation & geological history

Formed when sand- or silt-sized sediment accumulated, compacted, and cemented, commonly by silica, calcite, or iron oxides; age and source basin cannot be determined from the image.

Uses & applications

Used as building stone, paving, aggregate, and landscaping rock; this ordinary cobble has little jewelry or collector value.

Geological facts

The rounded shape indicates transport and abrasion by a river, beach, or glacial process; its brown color likely reflects iron-oxide staining and weathering.

Field identification & locations

Look for visible grains, bedding, and a gritty texture; a steel nail may scratch softer varieties, while dilute hydrochloric acid fizzes if calcite cement is present. Common in sedimentary terrains and stream gravels worldwide.