sedimentary

Weathered limestone or concrete-like calcareous rock

Limestone; predominantly calcite (CaCO₃), possibly containing dolomite and silicate impurities

AI-generated identification · may be incorrect

Pale gray to cream, dull and highly weathered, with granular/porous texture; calcite hardness ~3, nonmetallic luster, rhombohedral cleavage, specific gravity ~2.7. The image alone cannot exclude a fragment of old concrete or mortar.

Identified August 28, 2026More sedimentary →

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At a glance

Common name: Weathered limestone or concrete-like calcareous rock
Scientific name: Limestone; predominantly calcite (CaCO₃), possibly containing dolomite and silicate impurities
Category: sedimentary
Identified: August 28, 2026
Method: Standard

AI Estimated Value

$0–$5 for an ordinary fragment; $10–$50 if fossiliferous, unusually textured, or a documented geological specimen.

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

Likely naturally deposited carbonate sediment later lithified in a shallow marine environment, commonly during Paleozoic–Mesozoic time; the irregular pale fragment may also be human-processed material. Effervescence with dilute hydrochloric acid strongly supports calcite-rich limestone.

Uses & applications

Limestone is used for aggregate, cement, lime, flux, soil conditioner, and building stone; ordinary weathered fragments have negligible jewelry or collector value.

Geological facts

Calcite-rich limestone commonly preserves fossils, bedding, and solution cavities. Acid fizzing is typically vigorous, whereas dolomitic rock reacts weakly unless powdered.

Field identification & locations

Common worldwide, especially in former shallow seas; major occurrences include the Appalachian region, Mediterranean, UK, and China. Check for acid reaction, fossil textures, and absence of uniform cement paste or manufactured aggregate.