fossil

Agatized Fossil Coral

Agatized Anthozoa

AI-generated identification · may be incorrect

Hardness: 6.5-7 (Mohs), Color: Translucent to opaque, varying colors including tan, orange, white, and gray, Luster: Vitreous to waxy, Crystal structure: Microcrystalline (chalcedony) replacing original aragonite/calcite structure, Cleavage: None

Hardness: 6

Identified August 25, 2026More fossil →

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Physical properties

Formation & geological history

Formed when prehistoric coral is gradually replaced by silica-rich water over millions of years, turning the coral into agate (chalcedony) while preserving its structural patterns.

Uses & applications

Commonly used in lapidary arts, wire-wrapped jewelry, cabochons, and as a collector's specimen.

Geological facts

Agatized fossil coral is the state rock of Florida. The distinct flower-like or star-like patterns are the preserved structural components of the ancient coral polyps.

Field identification & locations

Identifiable by its distinct, recurring geometric or star-like patterns within a hard, silica-based matrix. Often found in specific regions like Florida, Georgia, and Indonesia. Look for the typical coral polyp structures preserved in chalcedony.