sedimentary

Limestone

Sedimentary Calcium Carbonate (CaCO3)

AI-generated identification · may be incorrect

Hardness: 3 (Mohs scale), Color: light grey to bluish-grey, Luster: dull to earthy, Structure: massive or bedded, Cleavage: poor/irregular, Specific Gravity: 2.3-2.7

Identified July 4, 2026More sedimentary →

Explore Limestone in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 3 (Mohs scale), Color: light grey to bluish-grey, Luster: dull to earthy, Structure: massive or bedded, Cleavage: poor/irregular, Specific Gravity: 2.3-2.7

Formation & geological history

Formed primarily from the accumulation of shell, coral, algal, and fecal debris in marine environments. It can also form chemically through the precipitation of calcium carbonate from lake or ocean water.

Uses & applications

Extensively used in construction as aggregate, for manufacturing cement, as a decorative building stone, and in agricultural lime for soil treatment.

Geological facts

Limestone makes up about 10% of the total volume of all sedimentary rocks. It is the primary host rock for many cave systems and karst landscapes due to its solubility in acid.

Field identification & locations

Identify in the field by its effervescence (bubbling) when a drop of diluted hydrochloric acid is applied. It is commonly found in ancient seabed locations or mountain ranges that were once submerged.