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

Petrified Wood

Agatized or Silicified Wood (SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7. Color: Tan, brown, white, sometimes gray or yellow. Luster: Waxy to vitreous. Crystal structure: Cryptocrystalline (microcrystalline quartz).

Hardness
6
Color
Tan, brown, white, sometimes gray or yellow
Luster
Waxy to vitreous
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Physical properties

Hardness: 6.5-7. Color: Tan, brown, white, sometimes gray or yellow. Luster: Waxy to vitreous. Crystal structure: Cryptocrystalline (microcrystalline quartz).

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 lapidary work, jewelry, ornamental carvings, and collected as a fossil specimen.

Geological facts

Petrified wood can preserve the original cellular structure of the wood down to the microscopic level. The colors are typically derived from impurities like iron or manganese.

Field identification & locations

Identify by looking for wood grain, bark textures, or tree rings preserved in stone. It feels heavy and dense like rock. Commonly found in areas with past volcanic activity and sedimentary basins.

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