sedimentary

Fossiliferous limestone (coral or shell-rich limestone)

Biogenic calcite limestone, mainly calcium carbonate (CaCO₃); exact fossil type is unclear from the image

AI-generated identification · may be incorrect

Pale cream to gray, dull-to-waxy surface, with abundant rounded cavities and visible shell- or coral-like fragments. Likely Mohs hardness 3; calcite is trigonal and has perfect rhombohedral cleavage, though the specimen’s porous, irregular texture makes testing difficult.

Identified October 3, 2026More sedimentary →

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At a glance

Common name: Fossiliferous limestone (coral or shell-rich limestone)
Scientific name: Biogenic calcite limestone, mainly calcium carbonate (CaCO₃); exact fossil type is unclear from the image
Category: sedimentary
Identified: October 3, 2026
Method: Standard

AI Estimated Value

About $5–$30 for a common hand-sized specimen; larger, well-preserved or identifiable fossils can be worth more.

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

Forms when calcareous shells, coral, or other marine debris accumulate and become cemented on a seafloor, commonly in warm, shallow water. Its geological age cannot be determined from the photograph.

Uses & applications

Limestone is widely used for cement and lime, building stone, and aggregate; fossil-rich pieces are mainly collected or displayed as decorative specimens.

Geological facts

The holes may be fossil structures or natural cavities, but the image alone cannot confirm whether this is coral, shell limestone, or another porous carbonate rock.

Field identification & locations

Look for fizzing with dilute acid, a relatively soft surface, and embedded fossil fragments; common settings include ancient reefs and marine sedimentary formations worldwide. Avoid acid-testing a valuable specimen.