Petrified Wood
Silicon Dioxide var. Petrified Wood (Pseudomorph of Quartz or Opal after Wood) · Semi-Precious Gemstone / Fossilized Mineral Specimen
Crystal System
Amorphous (Opaline) to Trigonal (Quartz-based); occurs in massive, woody pseudomorphic habit
Mineral Group
Silicates (Tectosilicates)
Chemical Formula
SiO2 · nH2O (Silica with trace impurities of Iron Oxide, Manganese, and Copper)
Formation Process
Sedimentary/Permineralization: Organic material is buried under sediment/ash; silica-rich groundwater replaces cell structures with minerals over millions of years.
About This Crystal
Opaque, blocky specimen with a fibrous or woody texture. Displays shades of beige, tan, and dark brown with visible longitudinal grain patterns mimicking tree bark or wood fibers. Luster is earthy to waxy.
Physical Characteristics
Color: Muted earth tones (brown, tan, cream); Streak: White; Cleavage: None; Fracture: Conchoidal to splintery; Specific Gravity: 2.6–2.9; Non-fluorescent.
Optical Properties
Opaque to occasionally translucent at edges; Refractive Index: 1.54–1.55 (Quartz) or 1.45 (Opaline); No pleochroism or dispersion.
Hardness & Durability
Origin Region
Arizona (USA), Madagascar, Indonesia, and Argentina. Found in sedimentary basins.
Hardness & Durability
Mohs Hardness: 6.5–7.0. Very durable and stable for jewelry or decorative use, comparable to Jasper or Agate.
Care & Maintenance
Clean with warm soapy water and a soft brush. Avoid ultrasonic cleaners if fractures are present. Generally resistant to sunlight and chemicals.
Rarity & Value
Common to Uncommon; Value depends on color vibrancy, size, and the preservation of biological detail (rings, bark).
Special Characteristics
Pseudomorphism: Maintains the physical structure of the original organic material while being chemically converted to stone.
Lore & History
Historically used in amulets and jewelry by ancient civilizations. Metaphysically associated with grounding, ancient wisdom, and the root chakra, symbolizing longevity and connection to the Earth.