sedimentary
Fossil Coral
Scleractinia (fossil order), primarily Calcium Carbonate (CaCO3)
Hardness: 3-4 (Mohs scale), Color: Cream, tan, or white, Luster: Dull to earthy, Structure: Visible coralline pores or septa, Cleavage: None
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3-4 (Mohs scale), Color: Cream, tan, or white, Luster: Dull to earthy, Structure: Visible coralline pores or septa, Cleavage: None
Formation & geological history
Formed from the skeletal remains of marine polyps in shallow tropical seas, typically during the Paleozoic or Mesozoic eras, later lithified into limestone.
Uses & applications
Used for geological study, decorative aquarium decor, jewelry (petrified versions), and as a calcium source in industry.
Geological facts
Agatized coral is the state rock of Florida; these fossils can be millions of years old and represent ancient reef systems that are now on dry land due to sea-level changes.
Field identification & locations
Look for small, repeated geometric holes (calices) or star-like patterns on the surface of a light-colored rock. Common in limestone quarries and coastal regions.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite
sedimentary