fossil

Fossil-bearing limestone, possibly a crinoid or shell fragment

Calcite (CaCO₃) limestone containing an indeterminate marine fossil

AI-generated identification · may be incorrect

Cream-to-gray, fine-grained carbonate rock with a dark fossil impression or fragment; calcite has Mohs hardness 3, vitreous-to-dull luster, rhombohedral cleavage, and specific gravity about 2.7. It should fizz with dilute hydrochloric acid or vinegar, though the fossil identity cannot be confirmed from one image.

Identified August 20, 2026More fossil →

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At a glance

Common name: Fossil-bearing limestone, possibly a crinoid or shell fragment
Scientific name: Calcite (CaCO₃) limestone containing an indeterminate marine fossil
Category: fossil
Identified: August 20, 2026
Method: Standard

AI Estimated Value

Approximately $5–$30 for a common hand specimen; $30–$100+ if the fossil is clearly identifiable, attractive, and professionally prepared.

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 marine carbonate mud and skeletal debris, later lithified into limestone; the specimen may date from Paleozoic or Mesozoic marine strata, but age requires locality information. The dark feature appears biological rather than a crystal vein.

Uses & applications

Used as a decorative or educational fossil specimen; limestone is widely used for cement, aggregate, lime, and building stone. Collector value is mainly aesthetic and depends on fossil clarity and preparation.

Geological facts

The visible structure could represent a shell, brachiopod, or crinoid fragment, but image-only identification is uncertain. Fossils are commonly preserved as molds, casts, or mineral-replaced remains in limestone.

Field identification & locations

Common in sedimentary exposures worldwide, especially former shallow seas; inspect bedding and look for repeated shell shapes or crinoid columnals. Avoid acid testing on valuable surfaces.