sedimentary
Coral Fossil (Favosites type)
Phylum Cnidaria, Class Anthozoa (often CaCO3 - Calcium Carbonate)
Hardness: 3.0-4.0 (Mohs scale); Color: White to grayish-white; Luster: Dull to earthy; Structure: Hexagonal or rounded honeycomb-like pores (corallites); Cleavage: None; Specific Gravity: 2.6-2.7
- Hardness
- 3
- Color
- White to grayish-white
- Luster
- Dull to earthy
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Physical properties
Hardness: 3.0-4.0 (Mohs scale); Color: White to grayish-white; Luster: Dull to earthy; Structure: Hexagonal or rounded honeycomb-like pores (corallites); Cleavage: None; Specific Gravity: 2.6-2.7
Formation & geological history
Formed in warm, shallow marine environments through the accumulation of skeletal remains from coral polyps. Most common specimens in this state date from the Ordovician to Devonian periods (approx. 488 to 359 million years ago).
Uses & applications
Used primarily for aquarium decor, landscaping, educational geological collections, and occasionally as a source of lime in cement production when found in large deposits.
Geological facts
Commonly referred to as 'Honeycomb Coral' due to the distinct cell pattern. These fossils are evidence of ancient oceans that once covered landmasses that are now dry and mountainous.
Field identification & locations
Identify in the field by looking for a 'pitted' or 'craters' surface on white/tan rock, often near limestone outcroppings. Common in the Great Lakes region (USA) and ancient reef beds globally.
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