fossil

Fossiliferous wood / petrified wood fragment

Silicified or partially mineralized wood (fossil wood; commonly quartz/chalcedony replacement)

AI-generated identification · may be incorrect

Brown-tan, layered woody grain and fibrous texture are visible; luster is dull to subvitreous, with no obvious cleavage. Typical hardness is about 6.5–7 if fully silicified, but this specimen appears partly weathered and may be softer; specific gravity commonly 2.2–2.7.

Identified September 5, 2026More fossil →

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At a glance

Common name: Fossiliferous wood / petrified wood fragment
Scientific name: Silicified or partially mineralized wood (fossil wood; commonly quartz/chalcedony replacement)
Category: fossil
Identified: September 5, 2026
Method: Standard

AI Estimated Value

About $5–$30 for a small common fragment; $30–$150+ if unusually detailed, colorful, or demonstrably from a desirable 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

Buried wood was preserved and gradually replaced by silica-rich groundwater, often during the Cenozoic or late Mesozoic; exact age cannot be determined from the photograph. It commonly forms in volcanic ash beds, river deposits, and sedimentary basins.

Uses & applications

Collected as a fossil and used for polished slabs, cabochons, bookends, and decorative objects; it has little construction value in fragment form.

Geological facts

The best identification clue is preserved cellular or growth-ring structure rather than ordinary sedimentary layering. Complete silicification can preserve microscopic wood anatomy in remarkable detail.

Field identification & locations

Common localities include Arizona, Colorado, Oregon, Madagascar, Indonesia, and Australia. Look for wood grain, cell patterns, a glassy fracture, and inability to scratch it with a steel knife; acid testing is generally unhelpful.