Fossiliferous Limestone
Limestone with fossil inclusions (CaCO3)
Rock Type: sedimentary

Physical Properties
Hardness: 3-4 on Mohs scale; Color: Gray, tan, or buff with visible whitish fossil fragments; Luster: Dull/Earthy; Structure: Clastic or Biogenic; Cleavage: None (conchoidal to irregular fracture).
Formation & Geological History
Formed in shallow, warm marine environments through the accumulation of shell, coral, algal, and fecal debris over millions of years. This specimen shows significant weathering and biogenic debris typical of Paleozoic or Mesozoic age deposits.
Uses & Applications
Used primarily in construction (crushed stone, cement), agriculture (lime), and as a collector's specimen for paleontological interest.
Geological Facts
Limestone makes up about 10% of the total volume of all sedimentary rocks. It often contains perfectly preserved organisms that lived millions of years ago. This particular piece appears to be a fragment of a larger bed containing brachiopods or crinoid stems.
Field Identification & Locations
Identify in the field by its reaction (fizzing) when exposed to dilute hydrochloric acid and the presence of visible fossil remains. It is found globally in regions that were once ancient sea beds.
Identified on: 5/9/2026
Mode: Standard