Petrified Wood

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Petrified wood is the fossilized remains of what once was wood. The material became petrified over time by the invasion of minerals into cavities between and within the cells of natural wood. Instead of decaying, the organic materials in the wood were replaced with minerals, primarily silicate of quartz, without changing the original structure of the wood.

Petrified Wood Polished
Petrified Wood Classification
Common Name Petrified Wood
Petrified Wood Optical Properties
Transparency Translucent - Opaque
Dispersion Strength: None
Refractive Index 1.535-1.539
Birefringence 0.004
Optic Character Uniaxial
Optic Sign Positive
Polariscope Reaction Aggregate (AGG)
Fluorescence SWUV: Inert
LWUV: Inert
Pleochroism None
Petrified Wood Characteristic Physical Properties
Hardness 6.5-7
Streak White
Specific Gravity 2.550-2.700 Typical:2.600
Toughness Excellent
Inclusions Petrified wood looks like a patterned jasper. Sometimes the structure of the original organic material is replicated when the quartz replaces the original material.
Luster Vitreous, Greasy
Stability Good
Fracture Conchoidal, Granular
Cleavage None
Petrified Wood Chemistry & Crystallography
Chemical Name silicon dioxide (aka silica)
Chemical Formula SiO2
Crystal System Trigonal
Chemistry Classification Silicate

Petrified Wood Colors

  • Brown Petrified Wood Brown
  • Yellow Petrified Wood Yellow
  • White Petrified Wood White
  • Red Petrified Wood Red
  • Purple Petrified Wood Purple
  • Pink Petrified Wood Pink
  • Orange Petrified Wood Orange
  • Multi-color Petrified Wood Multi-color
  • Green Petrified Wood Green
  • Gray Petrified Wood Gray
  • Colorless Petrified Wood Colorless
  • Blue Petrified Wood Blue
  • Black Petrified Wood Black
  • Bi-color Petrified Wood Bi-color

Alternate Names

Agatized Wood Or Silicified Wood

Countries of Origin

United States of America (the)


Normal care

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This page was created on June 27, 2014.

This page was last edited on October 24, 2019.