fossil

Fossiliferous limestone (likely crinoidal or shell limestone)

Calcite-rich limestone; predominantly CaCO₃, with visible fossil fragments

AI-generated identification · may be incorrect

Typically Mohs hardness 3, white to tan-gray, earthy to dull luster, fine- to medium-grained carbonate matrix, and irregular fossil molds or cross-sections. It reacts vigorously with dilute hydrochloric acid or household vinegar, especially on a freshly scratched surface.

Identified August 8, 2026More fossil →

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At a glance

Common name: Fossiliferous limestone (likely crinoidal or shell limestone)
Scientific name: Calcite-rich limestone; predominantly CaCO₃, with visible fossil fragments
Category: fossil
Identified: August 8, 2026
Method: Standard

AI Estimated Value

About $2-$15 for a common loose specimen; $20-$75 if the fossil structures are clearly identifiable, well preserved, or locally significant.

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 marine shells, crinoid debris, or other carbonate organisms accumulate and lithify in shallow seas; the specimen may date from Paleozoic to Mesozoic marine strata, but its exact age cannot be determined from the image.

Uses & applications

Used as crushed stone, cement and lime feedstock, aggregate, and building stone; attractive fossiliferous pieces are collected or polished as decorative stone.

Geological facts

The rounded, patterned structures appear fossil-related, but image resolution prevents a confident identification of the organism. Orange-brown areas are likely iron-oxide staining or weathered surfaces.

Field identification & locations

Common in marine sedimentary formations worldwide, including the Midwest and Appalachian regions of North America, England, and parts of Europe. Confirm it by acid testing and examining the patterns with a hand lens; it is not an igneous, metamorphic, or gemstone specimen.