fossil

Polished fossil coral

Agatized or silicified coral, commonly fossilized stony coral (Scleractinia); exact genus cannot be determined from the image

AI-generated identification · may be incorrect

Cream-white silicified carbonate with orange-brown iron-oxide staining and a polished, waxy-to-vitreous luster; quartz-rich material has Mohs hardness about 6.5–7, while unsilicified coral is about 3–4. Original coral structures may appear as tiny corallite pits or honeycomb patterns.

Identified August 23, 2026More fossil →

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At a glance

Common name: Polished fossil coral
Scientific name: Agatized or silicified coral, commonly fossilized stony coral (Scleractinia); exact genus cannot be determined from the image
Category: fossil
Identified: August 23, 2026
Method: Standard

AI Estimated Value

About $10–$50 for a small polished carving; $50–$150+ for unusually detailed, attractive, or well-documented specimens.

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

Ancient reef coral was buried and mineral-replaced by silica-rich groundwater, often during the Paleozoic or Mesozoic; the specimen’s precise age requires locality information.

Uses & applications

Used as a lapidary carving, cabochon, or jewelry and collected as a fossil; it is not generally used for construction.

Geological facts

Polishing can reveal coral growth architecture while iron oxides create the orange veining. Some marketed “fossil coral” is actually calcitic coral rather than fully silicified material.

Field identification & locations

Look for repeated corallite cells, radial walls, and organic growth patterns rather than random veining; common sources include Indonesia, Madagascar, Morocco, Florida, and Utah. Avoid acids and test hardness discreetly because treatment or calcite composition may vary.