fossil

Likely petrified wood

Silicified wood, chiefly microcrystalline quartz (SiO₂)

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; brown, black, tan, and gray with a dull to waxy luster. The uneven surface and possible fibrous/grain-like banding are consistent with quartz-replaced wood, though the image is insufficient for certainty; cleavage is absent and fracture is typically splintery to conchoidal.

Identified August 10, 2026More fossil →

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Physical properties

Formation & geological history

Groundwater gradually replaced wood tissues with silica during burial, preserving cellular structure; coloration commonly comes from iron, manganese, or carbon. Ages range from tens of thousands to hundreds of millions of years, depending on the deposit.

Uses & applications

Used as a lapidary material for cabochons, carvings, polished slabs, and collectibles; large patterned pieces may have modest decorative value.

Geological facts

Petrified wood is a fossil rather than a conventional rock, and some specimens preserve growth rings or cellular detail at microscopic scale.

Field identification & locations

Look for wood grain, growth rings, bark texture, or cellular patterns, plus quartz-like hardness and a nonmetallic feel. Common localities include Arizona, Indonesia, Madagascar, Australia, and the western United States.