sedimentary
Fossiliferous Limestone
Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)
Hardness: 3 on the Mohs scale; Color: Gray to brownish-grey with darker fossil inclusions; Luster: Dull to earthy; Crystal structure: Microcrystalline to cryptocrystalline calcite; Cleavage: Perfect rhombohedral in calcite crystals; Specific Gravity: 2.7.
- Hardness
- 3 on the Mohs scale
- Color
- Gray to brownish-grey with darker fossil inclusions
- Luster
- Dull to earthy
Identified More sedimentary →
Explore Fossiliferous Limestone in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3 on the Mohs scale; Color: Gray to brownish-grey with darker fossil inclusions; Luster: Dull to earthy; Crystal structure: Microcrystalline to cryptocrystalline calcite; Cleavage: Perfect rhombohedral in calcite crystals; Specific Gravity: 2.7.
Formation & geological history
Formed in marine environments through the accumulation and compaction of shell, coral, algal, and fecal debris, often dating back hundreds of millions of years.
Uses & applications
Used in construction, production of lime and cement, aggregate in roads, and collected by fossil enthusiasts.
Geological facts
Limestone formations often preserve delicate prehistoric marine life, providing a clear window into ancient ocean ecosystems.
Field identification & locations
Can be identified in the field by its effervescence (fizzing) when exposed to weak hydrochloric acid due to the presence of calcium carbonate, alongside visible fossil fragments.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary
Fossiliferous Concretion
Septarian Concretion containing Brachiopods/Crinoids
fossil
Banded Siltstone / Mudstone Pebble
Siltstone / Argillite
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary
Shale
Shale (clastic sedimentary rock)
sedimentary