sedimentary

Fossiliferous Limestone

Fossiliferous Calcilutite / Biomicrite

AI-generated identification · may be incorrect

Hardness: 3-4 (Mohs scale), Color: Dirty gray to tan with brown fossil inclusions, Luster: Dull or earthy, Texture: Fine-grained matrix containing visible fossil fragments.

Identified June 12, 2026More sedimentary →

Explore Fossiliferous Limestone in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 3-4 (Mohs scale), Color: Dirty gray to tan with brown fossil inclusions, Luster: Dull or earthy, Texture: Fine-grained matrix containing visible fossil fragments.

Formation & geological history

Formed in warm, shallow marine environments through the accumulation of calcium carbonate and the skeletal remains of marine organisms. This specimen likely contains fragments of crinoids or small shells from the Paleozoic or Mesozoic eras.

Uses & applications

Primarily used for geological education, lime production, construction aggregate, and as decorative stone in architecture.

Geological facts

Fossiliferous limestone often acts as a natural record of prehistoric oceans; many specimens can date back hundreds of millions of years and map changes in sea levels.

Field identification & locations

Identify by a dull finish that fizzes when exposed to weak acid (dilute HCl) and the presence of small, imprinted biological patterns. Commonly found in riverbeds or coastal cliffs where ancient seabed layers are exposed.