sedimentary

Limestone (Karst formation)

Calcium Carbonate (CaCO3)

AI-generated identification · may be incorrect

Hardness: 3 on Mohs scale; Color: Light gray, white, or buff; Luster: Dull to earthy; Cleavage: Non-cleavable in bulk rock, rhombohedral in calcite crystals; Specific Gravity: 2.5 - 2.7.

Hardness: 3 on Mohs scale
Color: Light gray, white, or buff
Luster: Dull to earthy

Identified July 26, 2026More sedimentary →

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Physical properties

Hardness: 3 on Mohs scale; Color: Light gray, white, or buff; Luster: Dull to earthy; Cleavage: Non-cleavable in bulk rock, rhombohedral in calcite crystals; Specific Gravity: 2.5 - 2.7.

Formation & geological history

Formed in shallow marine environments from the accumulation of coral, shell fragments, and algal debris over millions of years, later subjected to chemical weathering creating dramatic karst terrain.

Uses & applications

Widely used in construction as crushed stone, concrete aggregate, lime production, dimension stone, and soil conditioning in agriculture.

Geological facts

Karst landscapes feature sinkholes, caves, and dramatic jagged rock formations created by acidic rainwater dissolving soluble limestone over thousands to millions of years.

Field identification & locations

Identify in the field by reacting (effervescing) with dilute hydrochloric acid, its light gray color, and weathered blocky or jagged joint patterns in mountainous exposures.