sedimentary
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Hardness: 3-4 (Mohs scale), Color: Pinkish-tan to reddish-brown with white inclusions, Luster: Dull to earthy, Structure: Clastic or bio-clastic, contains visible fossil fragments, Cleavage: None (conchoidal fracture), Specific Gravity: 2.5-2.7
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3-4 (Mohs scale), Color: Pinkish-tan to reddish-brown with white inclusions, Luster: Dull to earthy, Structure: Clastic or bio-clastic, contains visible fossil fragments, Cleavage: None (conchoidal fracture), Specific Gravity: 2.5-2.7
Formation & geological history
Formed in warm, shallow marine environments from the accumulation of organic debris such as shell fragments, coral, and algae. The pink hue suggests iron oxide presence during lithification through compaction and cementation.
Uses & applications
Primarily used as a construction aggregate, for making cement, decorative garden stones, and occasionally as a source of lime for soil treatment.
Geological facts
This specimen contains visible fossil fragments, likely crinoids or shell casts. Limestone covers about 10% of the Earth's total land area and is the primary rock found in karst landscapes.
Field identification & locations
Identify in the field by its reaction (fizzing) with dilute hydrochloric acid and the presence of visible fossil remains or small shell pieces. Common in regions that were once ancient sea beds.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite
sedimentary