sedimentary
Limestone (Karst formation)
Calcium Carbonate (CaCO3)
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
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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.
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