sedimentary
Fossiliferous Limestone (Coral Fossil)
Scleractinian Coral in Calcium Carbonate (CaCO3)
Hardness: 3-4 (Mohs scale); Color: Cream, tan, or light grey; Luster: Dull to earthy; Structure: Highly porous with visible bio-organic patterns (calice structures); Specific Gravity: 2.3-2.7.
- Hardness
- 3-4 (Mohs scale)
- Color
- Cream, tan, or light grey
- Luster
- Dull to earthy
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Physical properties
Hardness: 3-4 (Mohs scale); Color: Cream, tan, or light grey; Luster: Dull to earthy; Structure: Highly porous with visible bio-organic patterns (calice structures); Specific Gravity: 2.3-2.7.
Formation & geological history
Formed through the accumulation of marine skeletons and the precipitation of calcium carbonate in shallow, warm marine environments. Often dates from the Devonian to Recent periods depending on location.
Uses & applications
Used primarily in landscaping, aquariums, and as a collector's specimen. In industry, limestone is used for cement manufacturing and architecture.
Geological facts
This specimen shows natural erosion from water, likely from a beach or riverbed, which highlights the internal coral skeleton. Fossil limestone provides essential data for paleoclimatology regarding ancient sea levels.
Field identification & locations
Identify in the field by the presence of small, repetitive geometric or biological pits and its high reactivity to dilute hydrochloric acid (acid fizz test). Often found on coasts or in ancient uplifted seabeds.
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