sedimentary
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with Bioclasts
Hardness: 3 (Mohs scale); Color: Cream, tan, or light grey; Luster: Dull/Earthy; Structure: Clastic or Bioclastic; Cleavage: None (fractures); Specific Gravity: 2.3-2.7
- Hardness
- 3 (Mohs scale)
- Color
- Cream, tan, or light grey
- Luster
- Dull/Earthy
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Physical properties
Hardness: 3 (Mohs scale); Color: Cream, tan, or light grey; Luster: Dull/Earthy; Structure: Clastic or Bioclastic; Cleavage: None (fractures); Specific Gravity: 2.3-2.7
Formation & geological history
Formed in shallow, calm, warm marine waters through the accumulation of shell, coral, algal, and fecal debris. Primarily Phanerozoic in age.
Uses & applications
Used as a primary source for lime and cement, in construction aggregate, as a soil conditioner in agriculture, and as a decorative stone.
Geological facts
This rock acts as a time capsule for ancient marine life. Over 10% of all sedimentary rocks are limestones, and they often contain visible fossils of brachiopods, crinoids, or gastropods.
Field identification & locations
Identify by a positive 'fizz' test with cold dilute hydrochloric acid. Look for visible shell fragments or small rounded inclusions (ooids) embedded in a fine-grained matrix.
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