sedimentary

Fossiliferous Limestone

Bioclastic Limestone (CaCO3)

AI-generated identification · may be incorrect

Hardness: 3-4 (Mohs scale), Color: tan to light grayish-brown, Luster: dull to earthy, Structure: clastic/fragmental with visible shells and crinoid stems, Reacts with HCl.

Identified July 20, 2026More sedimentary →

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Physical properties

Hardness: 3-4 (Mohs scale), Color: tan to light grayish-brown, Luster: dull to earthy, Structure: clastic/fragmental with visible shells and crinoid stems, Reacts with HCl.

Formation & geological history

Formed in shallow, calm, warm marine waters from the accumulation of shell, coral, algal, and fecal debris. These rocks often date back hundreds of millions of years to the Paleozoic or Mesozoic eras.

Uses & applications

Used in construction as a building material, as a component of cement, for soil neutralization in agriculture, and as a source for lime.

Geological facts

This specimen appears to contain crinoid stem fragments and small shell impressions. Visible fossils suggest it was part of an ancient sea floor preserved over geological time.

Field identification & locations

Identify by looking for visible fossil fragments and testing with a drop of vinegar (weak acid) to see if it fizzes. Commonly found in areas that were once covered by ancient inland seas.