fossil

Polished fossilized wood

Silicified wood (petrified wood), commonly quartz/chalcedony replacing wood

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; brown, tan, and cream with a glossy polish, opaque to slightly translucent edges, and microcrystalline quartz structure. The elongated cavities and flowing grain-like pattern are consistent with preserved wood tissue and mineral-filled voids.

Identified September 11, 2026More fossil →

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Physical properties

Formation & geological history

Buried wood was gradually replaced or infused by silica-rich groundwater, preserving cellular structure; many specimens formed during the Cenozoic or Mesozoic, though age depends on locality. Common settings include volcanic ash beds, floodplains, and sedimentary deposits.

Uses & applications

Used as a lapidary material for cabochons, carvings, bookends, and decorative polished specimens. It is generally a collectible fossil rather than a construction stone.

Geological facts

Unlike ordinary wood, petrified wood is mineralized and will not burn; visible pores, growth patterns, and agatized cavities can remain. The specimen appears tumbled or cabochon-polished.

Field identification & locations

Identify by checking for wood grain, cellular pores, concentric growth patterns, and quartz-like hardness; it should scratch glass but not be scratched by a steel knife. Common sources include Arizona, Indonesia, Madagascar, Australia, and Argentina.