Rock Identifier
Petrified Wood (Silicified wood (primarily quartz, SiO2)) — fossil
fossil

Petrified Wood

Silicified wood (primarily quartz, SiO2)

AI-generated identification · may be incorrect

Hardness of 7 on the Mohs scale, earthy to vitreous luster, amorphous crystal structure replacing organic cellular material, and specific gravity around 2.5-2.7.

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Physical properties

Hardness of 7 on the Mohs scale, earthy to vitreous luster, amorphous crystal structure replacing organic cellular material, and specific gravity around 2.5-2.7.

Formation & geological history

Formed over millions of years through permineralization, where groundwater rich in dissolved silica replaces buried organic wood tissue.

Uses & applications

Used for decorative carvings, lapidary art, high-end display specimens, and gemstone jewelry.

Geological facts

Famous occurrences include the Petrified Forest National Park in Arizona, featuring specimens dating back over 200 million years to the Triassic period.

Field identification & locations

Identified by preserved tree ring patterns, bark texture, and a high weight despite wooden appearance; found globally in sedimentary rock layers.

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