sedimentary

Weathered limestone

Calcite-rich carbonate rock, predominantly CaCO₃ (often micritic or bioclastic limestone)

AI-generated identification · may be incorrect

Cream to tan, dull earthy luster, porous and heavily weathered; calcite hardness is about Mohs 3, with irregular fracture and weak-to-indistinct cleavage in the rock. It should fizz vigorously with dilute hydrochloric acid or strong vinegar if calcitic.

Identified September 5, 2026More sedimentary →

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At a glance

Common name: Weathered limestone
Scientific name: Calcite-rich carbonate rock, predominantly CaCO₃ (often micritic or bioclastic limestone)
Category: sedimentary
Identified: September 5, 2026
Method: Standard

AI Estimated Value

Usually $1–$10 for an ordinary fragment; $10–$50 or more if it contains distinctive fossils, unusual textures, or comes from a documented locality.

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 by accumulation and lithification of carbonate mud, shells, or other marine sediments, commonly in shallow warm seas; age cannot be determined from the photograph. Weathering and dissolution produced the cavities and rough surface.

Uses & applications

Used as crushed aggregate, cement and lime feedstock, building stone, and occasionally as a fossil-bearing or educational specimen; this fragment has little jewelry value.

Geological facts

Limestone is one of Earth’s most widespread sedimentary rocks and commonly preserves marine fossils, though none are clearly identifiable here.

Field identification & locations

Common worldwide, especially in former shallow-marine basins and karst regions. Confirm identification with an acid-fizz test, relatively low hardness, and a white powder or streak; distinguish it from dolostone, which reacts weakly unless powdered.