sedimentary
Fossiliferous Limestone
Fossiliferous Calcite (CaCO3)
Hardness: 3 (Mohs scale); Color: Tan, beige, grey; Luster: Dull to earthy; Structure: Clastic/Biogenic matrix; Cleavage: Rhombohedral in calcite crystals but often obscured by fossils.
- Hardness
- 3 (Mohs scale)
- Color
- Tan, beige, grey
- Luster
- Dull to earthy
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3 (Mohs scale); Color: Tan, beige, grey; Luster: Dull to earthy; Structure: Clastic/Biogenic matrix; Cleavage: Rhombohedral in calcite crystals but often obscured by fossils.
Formation & geological history
Formed in shallow marine environments over millions of years through the accumulation of calcium carbonate and organic debris (shells, coral) which are then lithified.
Uses & applications
Used in construction, as a source of lime for cement, in soil acidity neutralization, and as a popular educational specimen for amateur fossil hunters.
Geological facts
Many limestones are effectively 'cemeteries' of ancient marine life. Those containing brachiopods or crinoids often date back to the Paleozoic era.
Field identification & locations
Identify by a positive acid test (fizzes with vinegar) and the visible presence of shell fragments or marine impressions. Commonly found in road cuts or stream beds in limestone-rich regions.
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