Rock Identifier
Petrified Wood (Silicified Wood (SiO2)) — fossil
fossil

Petrified Wood

Silicified Wood (SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7 (Mohs scale), Color: tan, brown, yellow, Luster: dull to waxy, Crystal structure: cryptocrystalline (microcrystalline quartz), Cleavage: none, Specific gravity: 2.58-2.91

Hardness
6
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Physical properties

Hardness: 6.5-7 (Mohs scale), Color: tan, brown, yellow, Luster: dull to waxy, Crystal structure: cryptocrystalline (microcrystalline quartz), Cleavage: none, Specific gravity: 2.58-2.91

Formation & geological history

Formed when plant material is buried by sediment and protected from decay by oxygen and organisms. Then, groundwater rich in dissolved solids flows through the sediment, replacing the original plant material with silica, calcite, pyrite, or another inorganic material such as opal.

Uses & applications

Used in jewelry, lapidary arts, home decor, and as a collector's item.

Geological facts

The Petrified Forest National Park in Arizona is famous for its large deposits of petrified wood. It can sometimes contain well-preserved cellular structures.

Field identification & locations

Identified by wood grain patterns, knot structures, and sometimes bark textures preserved in stone. Found globally in sedimentary deposits.

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