Rock Identifier
Fossiliferous shale or mudstone with plant fossils (Carbonaceous mudstone/shale containing fossilized foliage, likely fern or seed-fern impressions) — fossil
fossil

Fossiliferous shale or mudstone with plant fossils

Carbonaceous mudstone/shale containing fossilized foliage, likely fern or seed-fern impressions

AI-generated identification · may be incorrect

Fine-grained brown to dark-gray sedimentary matrix with pale fossil impressions or mineralized fragments; typically Mohs 2–3, dull to earthy luster, very fine clastic texture, and fissile layering. The fossils appear as flattened molds or replacements rather than crystals.

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Physical properties

Fine-grained brown to dark-gray sedimentary matrix with pale fossil impressions or mineralized fragments; typically Mohs 2–3, dull to earthy luster, very fine clastic texture, and fissile layering. The fossils appear as flattened molds or replacements rather than crystals.

Formation & geological history

Formed when organic-rich mud buried and compacted in a quiet swamp, lake, or floodplain during the Paleozoic or Mesozoic; exact age and species require the museum label or locality. Fossil leaves and stems were preserved by carbon films, impressions, or mineral replacement.

Uses & applications

Primarily used for education, museum display, and collecting; it has little industrial or jewelry value, although some fossil slabs are decorative.

Geological facts

The specimen preserves biological shapes in sediment rather than being a mineral crystal. Nearby display material appears to include a fern fossil slab, suggesting a plant-fossil exhibit.

Field identification & locations

Identify it by thin bedding, soft brown matrix, and repeated leaf or stem outlines with no glassy crystal faces; avoid acid and excessive moisture. Common occurrences include coal-bearing basins and lacustrine fossil beds worldwide.

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Probable fossil-bearing rock or mineral concretion

Unidentified carbonate-rich concretion with a possible fossil inclusion

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Likely fossil oyster shell

Fossilized bivalve shell; exact species cannot be identified from the image

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Crinoid Stem Fossil in Matrix (Phylum Echinodermata, Class Crinoidea) — fossil

Crinoid Stem Fossil in Matrix

Phylum Echinodermata, Class Crinoidea

fossil
Fossiliferous limestone (likely a crinoidal or shell-fragment limestone) (Bioclastic limestone, composed chiefly of calcite (CaCO₃)) — sedimentary

Fossiliferous limestone (likely a crinoidal or shell-fragment limestone)

Bioclastic limestone, composed chiefly of calcite (CaCO₃)

sedimentary
Porous limestone pebble (Calcite-rich limestone (primarily CaCO₃); exact identification is uncertain from the image) — sedimentary

Porous limestone pebble

Calcite-rich limestone (primarily CaCO₃); exact identification is uncertain from the image

sedimentary
Weathered fossil bone fragment (identification uncertain) (Fossilized bone; exact taxon and mineral composition cannot be determined from the image) — fossil

Weathered fossil bone fragment (identification uncertain)

Fossilized bone; exact taxon and mineral composition cannot be determined from the image

fossil