fossil

Fossil Coral

Anthozoa fossil (Calcite / SiO2 replacement)

Hardness: 3 (if calcite) to 7 (if silicified/agateized). Color: Tan, beige, brown, and grey. Luster: Dull to vitreous. Structure: Distinct parallel ridges or corallite septa pattern.

Hardness: 3 (if calcite) to 7 (if silicified/agateized)
Color: Tan, beige, brown, and grey
Luster: Dull to vitreous

Identified July 26, 2026More fossil →

Explore Fossil Coral in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 3 (if calcite) to 7 (if silicified/agateized). Color: Tan, beige, brown, and grey. Luster: Dull to vitreous. Structure: Distinct parallel ridges or corallite septa pattern.

Formation & geological history

Formed in warm, shallow marine waters where ancient coral polyps deposited calcium carbonate skeletons. Over millions of years, the remains were buried and petrified or silicified.

Uses & applications

Used for educational display, lapidary art, jewelry, and paleontology collections.

Geological facts

Corals have existed on Earth for over 400 million years. Some ancient fossil corals, like Petoskey stones, are popular state stones and collector items.

Field identification & locations

Identified by fine parallel or radial ridges indicative of ancient coral wall structures. Commonly found along lake shores, riverbeds, and limestone exposures.

Other fossil specimens

See all

Crinoid Stem Fossil in Matrix

Phylum Echinodermata, Class Crinoidea

fossil

Sedimentary Outcrop (Sandstone/Shale)

Sedimentary bedrock formation (variable composition)

sedimentary

Chert with Fossil Brachiopod

Microcrystalline Quartz (SiO2) with Calcitic Brachiopod inclusion

sedimentary

Fossilized Crinoid Stem in Limestone

Crinoidea (Class) in Calcium Carbonate (CaCO3) matrix

fossil

Fossiliferous Limestone

Limestone with embedded fossil cross-section

sedimentary

Fossiliferous Limestone

Fossiliferous Calcilutite / Biomicrite

sedimentary