sedimentary
Limestone Cobble
Sedimentary Limestone (Calcium Carbonate, CaCO3)
AI-generated identification · may be incorrectHardness: 3-4 (Mohs scale), Color: tan to gray, Luster: dull/earthy, Structure: fine-grained/micritic, Specific Gravity: approx. 2.5-2.7
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: tan to gray, Luster: dull/earthy, Structure: fine-grained/micritic, Specific Gravity: approx. 2.5-2.7
Formation & geological history
Formed in marine environments through the accumulation of shell, coral, algal, and fecal debris. These rocks can date back hundreds of millions of years and typically form in warm, shallow coastal waters.
Uses & applications
Used in the production of cement, as a building stone, crushed for road base, and in the chemical industry to neutralize acidity in soil and water.
Geological facts
Limestone makes up about 10% of the total volume of all sedimentary rocks. It is the primary parent rock for karst topography, including caves and sinkholes.
Field identification & locations
Identify in the field by its softness (it can be scratched by a steel nail) and its energetic reaction (fizzing) when exposed to a weak acid like vinegar or hydrochloric acid.
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