Rock Identifier
Petrified Wood (Silicified wood (Quartz replacement of organic matter)) — fossil
fossil

Petrified Wood

Silicified wood (Quartz replacement of organic matter)

AI-generated identification · may be incorrect

Hardness of 6.5-7 on the Mohs scale, variable wood-like colors (brown, tan, red), vitreous to waxy luster, microcrystalline quartz crystal structure, specific gravity 2.5-2.7.

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Physical properties

Hardness of 6.5-7 on the Mohs scale, variable wood-like colors (brown, tan, red), vitreous to waxy luster, microcrystalline quartz crystal structure, specific gravity 2.5-2.7.

Formation & geological history

Formed when buried wood is slowly replaced by silica-rich groundwater under anoxic conditions, often dating back millions of years.

Uses & applications

Used in decorative items, jewelry, high-end lapidary work, and appreciated by fossil and mineral collectors.

Geological facts

The organic structure of the original tree, including growth rings and cellular details, is frequently preserved in microscopic detail.

Field identification & locations

Identify by wood-like grain and texture combined with stone-like weight and hardness; commonly found in ancient river floodplains and volcanic ash beds worldwide.

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