sedimentary

Limestone

Calcium Carbonate (CaCO3)

AI-generated identification · may be incorrect

Hardness: 3 on Mohs scale; Color: light grey to white with weathered pitted surface; Luster: dull to earth; Crystal Structure: Trigonal (as calcite microcrystals); Cleavage: Perfect rhombohedral in calcite grains; Specific Gravity: 2.5-2.7

Hardness: 3 on Mohs scale
Color: light grey to white with weathered pitted surface
Luster: dull to earth

Identified July 26, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed in warm, shallow marine environments through the accumulation and compaction of organic debris like shells, coral, and algal remains over millions of years.

Uses & applications

Extensively used in construction, cement production, crushed stone aggregate, soil acidity neutralizer in agriculture, and chemical feedstock.

Geological facts

Limestone landscapes often develop karst features, including caves, sinkholes, and underground drainage systems, due to the rock's solubility in slightly acidic rainwater.

Field identification & locations

Identified in the field by its light grey color, characteristic dissolution fluting or weathering pits, and strong reaction (fizzing) when exposed to dilute hydrochloric acid.