sedimentary

Fossiliferous Limestone (or Bryozoan/Coral Fossil Pebble)

Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)

Hardness: 3 on Mohs scale. Color: Brownish-tan with white fossil impressions (molds and casts). Luster: Dull to earthy. Structure: Granular to massive sedimentary rock containing visible fossil fragments.

Hardness: 3 on Mohs scale
Color: Brownish-tan with white fossil impressions (molds and casts)
Luster: Dull to earthy

Identified August 5, 2026More sedimentary →

Explore Fossiliferous Limestone (or Bryozoan/Coral Fossil Pebble) in the encyclopedia →

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Physical properties

Formation & geological history

Formed in shallow marine environments over millions of years through the accumulation of skeletal fragments of marine organisms like bryozoans, crinoids, or corals, which were later cemented by calcite.

Uses & applications

Educational purposes, fossil collecting, and occasionally used in landscaping or decorative stone.

Geological facts

Rocks like this act as ancient snapshots of shallow prehistoric seas, preserving the intricate calcium carbonate structures of sea life from geological periods such as the Paleozoic or Mesozoic.

Field identification & locations

Can be identified in the field by its reaction to dilute hydrochloric acid (effervescence due to calcite) and the distinct pattern of fossil impressions or skeletal fragments on its weathered surface. Commonly found in riverbeds, beaches, and sedimentary outcrops.

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Sandstone or Siltstone

Arenite (if sandstone)

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Fossiliferous Concretion

Septarian Concretion containing Brachiopods/Crinoids

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Quartz pebble

Silicon dioxide (SiO2)

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Generic Pebble / Rock Fragment

Lithic fragment / Weathered rock

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Sedimentary Sandstone

Arenite (Sedimentary Rock)

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Banded Siltstone / Mudstone Pebble

Siltstone / Argillite

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