sedimentary
Fossiliferous Limestone
Limestone (CaCO3 - Calcium Carbonate)
Hardness: 3 (Mohs scale); Color: Tan, beige, or gray; Luster: Dull/Earthy; Structure: Clastic or Biogenic; Cleavage: None; Specific Gravity: 2.3-2.7
- Hardness
- 3 (Mohs scale)
- Color
- Tan, beige, or gray
- Luster
- Dull/Earthy
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Physical properties
Hardness: 3 (Mohs scale); Color: Tan, beige, or gray; Luster: Dull/Earthy; Structure: Clastic or Biogenic; Cleavage: None; Specific Gravity: 2.3-2.7
Formation & geological history
Formed in shallow, calm, warm marine waters by the accumulation of shell, coral, algal, and fecal debris. This specimen appears to be a water-worn river pebble or beach stone consisting of lithified marine sediments.
Uses & applications
Used in construction, lime production, cement, and as a soil conditioner. Fossil-rich specimens are popular with collectors and used in decorative stone.
Geological facts
Limestone makes up about 10% of the total volume of all sedimentary rocks on Earth. This specific specimen shows pits and molds where organic matter or softer minerals have weathered away.
Field identification & locations
Identify by its reaction (fizzing) with diluted hydrochloric acid. Look for visible shell fragments or small circular patterns (crinoids/ooids). Commonly found in ancient inland sea beds.
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