sedimentary
Limestone / Dolomite
Calcium Carbonate (CaCO3) / Calcium Magnesium Carbonate (CaMg(CO3)2)
Hardness: 3-4 on Mohs scale; Color: Light gray to off-white; Luster: Dull to earthy; Texture: Fine-grained to crystalline; Specific Gravity: 2.5-2.7
- Hardness
- 3-4 on Mohs scale
- Color
- Light gray to off-white
- Luster
- Dull to earthy
Identified More sedimentary →
Explore Limestone / Dolomite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3-4 on Mohs scale; Color: Light gray to off-white; Luster: Dull to earthy; Texture: Fine-grained to crystalline; Specific Gravity: 2.5-2.7
Formation & geological history
Formed primarily in shallow, warm marine environments through the accumulation of organic debris like shells, coral, and algal remains, or chemical precipitation of calcium carbonate over millions of years.
Uses & applications
Extensively used as crushed stone for road construction, concrete aggregate, flux in steelmaking, soil acid neutralizer in agriculture, and building stone.
Geological facts
Limestone is the primary ingredient in Portland cement. Vast limestone karst landscapes around the world contain major cave systems created by water dissolving the carbonate rock.
Field identification & locations
Identified by its softness (can be scratched with a steel nail) and strong effervescence (fizzing) when exposed to dilute acid like vinegar. Commonly found in quarries, roadcuts, and riverbeds.
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
Shale
Shale (clastic sedimentary rock)
sedimentary
Shale
Argillaceous sedimentary rock
sedimentary
Mudstone
Argillite / Siliciclastic sedimentary rock
sedimentary