fossil

Fossil coral fragment (probable)

Recrystallized fossil coral, commonly scleractinian or tabulate coral; exact identification requires magnification and locality

AI-generated identification · may be incorrect

Cream to tan, irregular rounded fragment with faint polygonal/cellular textures and a dull earthy luster. The original calcite/aragonite skeleton is likely recrystallized calcite (Mohs hardness ~3), with no obvious cleavage; it fizzes in dilute hydrochloric acid if carbonate-rich.

Identified August 8, 2026More fossil →

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At a glance

Common name: Fossil coral fragment (probable)
Scientific name: Recrystallized fossil coral, commonly scleractinian or tabulate coral; exact identification requires magnification and locality
Category: fossil
Identified: August 8, 2026
Method: Standard

AI Estimated Value

About $5–$25 for a small common fragment; $30–$100+ if clearly patterned, well-preserved, or from a documented locality.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

Formed when a colonial coral skeleton was buried in marine sediment and mineralized or recrystallized during diagenesis, commonly during the Paleozoic or Mesozoic. Age cannot be determined from the photograph alone.

Uses & applications

Primarily a collector, educational, or decorative specimen; polished fossil coral is sometimes used in jewelry and ornament. Value is generally modest unless the species, locality, preservation, or provenance is notable.

Geological facts

Fossil coral commonly preserves repeating corallite patterns—small honeycomb, honeycomb-like, or star-shaped chambers—rather than random rock texture.

Field identification & locations

Inspect with a loupe for repeated polygonal cells or radiating septa; compare hardness and acid reaction with limestone. Commonly found in ancient marine limestones and uplifted reef deposits worldwide.