sedimentary
Limestone
Calcium Carbonate (CaCO3)
Hardness: 3 on Mohs scale; Color: Light gray to off-white; Luster: Dull to earthy; Texture: Fine-grained, microcrystalline to bioclastic
- Hardness
- 3 on Mohs scale
- Color
- Light gray to off-white
- Luster
- Dull to earthy
Identified More sedimentary →
Explore Limestone in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3 on Mohs scale; Color: Light gray to off-white; Luster: Dull to earthy; Texture: Fine-grained, microcrystalline to bioclastic
Formation & geological history
Formed primarily in shallow, warm marine environments through the accumulation and compaction of shells, coral, algal debris, and chemical precipitation of calcium carbonate.
Uses & applications
Widely used in construction aggregate, cement production, soil conditioning, crushed stone, and industrial chemical processing.
Geological facts
Limestone accounts for about 10% of the total volume of all sedimentary rocks on Earth and is the primary rock type in karst landscapes, which feature caves and sinkholes.
Field identification & locations
Can be easily identified in the field by testing with dilute hydrochloric acid, which causes it to effervesce (fizz) vigorously. It is commonly found in ancient seabed deposits worldwide.
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 fragment
Shale (clay mineral rich sedimentary rock)
sedimentary
Shale / Mudstone
Sedimentary rock (Claystone / Mudstone / Shale)
sedimentary