sedimentary

Weathered limestone or calcareous sandstone

Likely micritic limestone (calcite, CaCO₃), possibly carbonate-rich sandstone

AI-generated identification · may be incorrect

Pale beige, fine-grained, dull to earthy luster, massive and strongly weathered; typically Mohs hardness 3 for limestone (up to 6–7 if quartz-rich sandstone), with no visible crystals or cleavage. Calcite-rich material should effervesce with dilute hydrochloric acid.

Identified August 11, 2026More sedimentary →

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At a glance

Common name: Weathered limestone or calcareous sandstone
Scientific name: Likely micritic limestone (calcite, CaCO₃), possibly carbonate-rich sandstone
Category: sedimentary
Identified: August 11, 2026
Method: Standard

AI Estimated Value

About $1–$15 for an ordinary hand specimen; $20–$100+ if it contains identifiable fossils, unusual texture, or strong decorative appeal.

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 from compacted carbonate mud or cemented carbonate sand in a marine or shoreline environment, usually over millions of years; the rounded shape and surface pits reflect erosion and weathering. Exact age cannot be determined from the image.

Uses & applications

Limestone is used for cement, aggregate, building stone, soil treatment, and chemical production; attractive pieces may be collected decoratively. Ordinary specimens have little commercial value.

Geological facts

The irregular dark seams may be bedding, fractures, or fossil-rich zones, though no diagnostic fossils are visible. Carbonate rocks commonly dissolve and develop cavities in mildly acidic water.

Field identification & locations

Common in sedimentary terrains worldwide, especially marine basins and former shorelines. Test a fresh edge with vinegar or dilute acid, inspect with a hand lens for shell fragments, and compare its gritty texture to sandstone.