fossil

Fossiliferous Limestone

Calcium carbonate (CaCO3) matrix with fossil inclusions

Hardness: 3 on Mohs scale (matrix); Color: Light tan, beige, brown, and grayish tones; Luster: Earthy to dull with occasional calcitic sparkle; Texture: Bioclastic, rough surface showing visible rings and fossil fragments

Hardness: 3 on Mohs scale (matrix)
Color: Light tan, beige, brown, and grayish tones
Luster: Earthy to dull with occasional calcitic sparkle

Identified July 26, 2026More fossil →

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Physical properties

Formation & geological history

Formed in shallow, warm marine environments through the accumulation and cementation of organic remains such as crinoid stems, shell fragments, and corals over millions of years (typically Paleozoic to Mesozoic era).

Uses & applications

Used as building stone, aggregate in concrete, soil conditioner, source of lime, and as educational or display specimens for fossil collectors.

Geological facts

The circular rings and patterns visible on the specimen's surface are cross-sections of ancient marine organism fossils, such as crinoid stem segments or small brachiopod shells, embedded in a fine-grained carbonate matrix.

Field identification & locations

Identified by its effervescence (fizzing) when exposed to weak acids like vinegar, tan-brown color, low hardness (easily scratched by steel), and embedded marine fossil structures. Frequently found in limestone riverbeds, gravel pits, and coastal areas.

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Crinoid Stem Fossil in Matrix

Phylum Echinodermata, Class Crinoidea

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Sedimentary bedrock formation (variable composition)

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Chert with Fossil Brachiopod

Microcrystalline Quartz (SiO2) with Calcitic Brachiopod inclusion

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Fossilized Crinoid Stem in Limestone

Crinoidea (Class) in Calcium Carbonate (CaCO3) matrix

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Fossiliferous Limestone

Limestone with embedded fossil cross-section

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Fossiliferous Limestone

Fossiliferous Calcilutite / Biomicrite

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