sedimentary

Weathered gray stone, possibly limestone or concrete-like carbonate rock

Tentatively micritic limestone (calcium carbonate, CaCO₃); exact identification is uncertain from the image

AI-generated identification · may be incorrect

Pale gray, dull and fine-grained with an irregular weathered surface; likely Mohs hardness 3, nonmetallic luster, and no visible crystals or cleavage. It may fizz with dilute hydrochloric acid or vinegar if carbonate-rich.

Identified August 12, 2026More sedimentary →

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At a glance

Common name: Weathered gray stone, possibly limestone or concrete-like carbonate rock
Scientific name: Tentatively micritic limestone (calcium carbonate, CaCO₃); exact identification is uncertain from the image
Category: sedimentary
Identified: August 12, 2026
Method: Standard

AI Estimated Value

Typically $1-$10 as an unproven common fragment; generally negligible if it is concrete or construction debris.

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

If limestone, it formed from compacted carbonate mud or microscopic marine shells, commonly during a shallow-marine sedimentary environment; its age cannot be determined visually.

Uses & applications

Limestone is used for aggregate, cement, lime, building stone, and soil treatment; small specimens have modest educational or collecting value.

Geological facts

The rounded shape and porous surface may reflect natural weathering, but the specimen could also be a fragment of cement, mortar, or another pale stone.

Field identification & locations

Test hardness against a steel nail and apply vinegar to a fresh surface; strong fizz supports calcite-rich limestone. Common sources include sedimentary basins worldwide.