sedimentary
Limestone Cobble
Carbonate Rock (CaCO3)
AI-generated identification · may be incorrectHardness: 3-4 (Mohs scale); Color: Gray to light tan; Luster: Dull/Earthy; Structure: Fine-grained with visible calcite veins; Cleavage: None (conchoidal fracture).
- Hardness
- 3-4 (Mohs scale)
- Color
- Gray to light tan
- Luster
- Dull/Earthy
Identified More sedimentary →
Explore Limestone Cobble in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3-4 (Mohs scale); Color: Gray to light tan; Luster: Dull/Earthy; Structure: Fine-grained with visible calcite veins; Cleavage: None (conchoidal fracture).
Formation & geological history
Formed from the accumulation of calcium carbonate (shells, coral, algal debris) in shallow marine environments. This specimen has been rounded by fluvial or glacial transport.
Uses & applications
Construction aggregate, cement production, soil conditioner (lime), and industrial chemical stabilizer.
Geological facts
Limestone covers about 10% of the Earth's land surface. It is the primary rock type in karst landscapes, known for creating dramatic caves and sinkholes.
Field identification & locations
Identify in the field by its readiness to fizz when exposed to weak acid (HCl). This specimen shows typical quartz or calcite micro-veins filling old fractures.
More like this
Other sedimentary specimens
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Generic Pebble / Rock Fragment
Lithic fragment / Weathered rock
sedimentary
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary