fossil

Polished fossilized wood (likely petrified wood)

Silicified wood; commonly quartz (SiO₂) replacing wood tissue

AI-generated identification · may be incorrect

Brown, elongated polished pebble with dark, wood-grain-like bands. Quartz-rich petrified wood has Mohs hardness about 6.5–7, vitreous to waxy luster, no obvious cleavage, and specific gravity near 2.5–2.7; exact identification requires magnification or testing.

Identified August 11, 2026More fossil →

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Physical properties

Formation & geological history

Buried woody tissue was mineralized as silica-bearing groundwater replaced cellular structures, commonly during the Mesozoic–Cenozoic (roughly 250–2 million years ago). The image may also show a polished wood-patterned jasper, so microscopic structure is important.

Uses & applications

Used as an ornamental stone, cabochons, carvings, bookends, and lapidary specimens; usually decorative rather than industrial.

Geological facts

Authentic petrified wood can preserve growth rings, vessels, and cellular detail while retaining the original shape of the wood.

Field identification & locations

Common in volcanic ash and sedimentary deposits, including Arizona, Utah, Oregon, Indonesia, and Madagascar. Look for continuous grain, cellular patterns, silica-like hardness, and lack of fibrous splintering; a steel file should not easily scratch it.