sedimentary

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

AI-generated identification · may be incorrect

Hardness: 3-4 (Mohs scale), Color: Dark grey to charcoal when wet, Luster: Dull/Earthy, Crystal Structure: Microcrystalline with visible bioclasts, Cleavage: None (conchoidal or irregular fracture)

Identified June 11, 2026More sedimentary →

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Physical properties

Hardness: 3-4 (Mohs scale), Color: Dark grey to charcoal when wet, Luster: Dull/Earthy, Crystal Structure: Microcrystalline with visible bioclasts, Cleavage: None (conchoidal or irregular fracture)

Formation & geological history

Formed in shallow marine environments from the accumulation of skeletal remains including crinoids, brachiopods, and bryozoans. These deposits often date back to the Paleozoic era (approx. 300-500 million years ago) and are consolidated through lithification.

Uses & applications

Used in the manufacturing of cement, as a decorative garden stone, and as aggregate for construction and roadbeds. High-quality specimens are popular for educational purposes and fossil hunting.

Geological facts

This specimen likely contains fragments of ancient marine life. Limestone covers about 10% of the Earth's total land area and is the primary rock type in which karst landscapes (caves and sinkholes) develop.

Field identification & locations

Identify in the field by checking for the presence of visible fossil fragments and its reaction to diluted hydrochloric acid (it will fizz). Commonly found in riverbeds, quarries, and outcrops within sedimentary basins.