sedimentary
Fossilized Shell in Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Hardness: 3 (Mohs scale), Color: Cream, off-white with purple/pink tinting, Luster: Dull to earthy, Structure: Amorphous/massive with visible biogenic pores, Cleavage: None (conchoidal fracture)
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Physical properties
Hardness: 3 (Mohs scale), Color: Cream, off-white with purple/pink tinting, Luster: Dull to earthy, Structure: Amorphous/massive with visible biogenic pores, Cleavage: None (conchoidal fracture)
Formation & geological history
Formed in shallow marine environments through the accumulation of shell, coral, algal, and fecal debris. This specimen shows a fossilized bivalve or brachiopod fragment embedded in a calcarenite matrix.
Uses & applications
Used in the manufacture of cement, as a decorative garden stone, and as a educational fossil specimen for hobbyists.
Geological facts
The small holes visible on the surface are likely 'borings' made by prehistoric sponges or worms (known as ichnofossils) while the shell was on the sea floor millions of years ago.
Field identification & locations
Identified by its reaction to dilute hydrochloric acid (it will fizz) and the presence of biological structures. Commonly found in coastal regions and ancient seabed outcrops.
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