sedimentary

Limestone (Flagstone)

Fossiliferous Limestone (CaCO3)

AI-generated identification · may be incorrect

Hardness: 3 on Mohs scale; Color: Tan, beige, grey; Luster: Dull to earthy; Structure: Biological sediment/clastic; Cleavage: None (conchoidal to uneven fracture); Specific Gravity: 2.5-2.7

Hardness: 3 on Mohs scale
Color: Tan, beige, grey
Luster: Dull to earthy

Identified April 12, 2026More sedimentary →

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Physical properties

Hardness: 3 on Mohs scale; Color: Tan, beige, grey; Luster: Dull to earthy; Structure: Biological sediment/clastic; Cleavage: None (conchoidal to uneven fracture); Specific Gravity: 2.5-2.7

Formation & geological history

Formed in marine environments from the accumulation of shell, coral, algal, and fecal debris. These specific specimens likely date from the Paleozoic or Mesozoic eras and were formed through lithification of calcium carbonate sediments.

Uses & applications

Primary uses include architectural flagstone, patio paving, garden walkways, and as a component in cement production or as crushed stone for road bases.

Geological facts

Limestone makes up about 10% of the total volume of all sedimentary rocks. It often contains visible fossils of ancient marine organisms, such as the small white shell fragments seen in this specimen.

Field identification & locations

Identify in the field by its softness (it can be scratched by a steel nail) and its effervescent reaction when touched with a weak acid like vinegar. Look for fossilized inclusions and bedding planes.