Petrified Wood
Silicified Wood / Quartz var. Chalcedony / Jasper · Decorative Stone / Mineral Specimen / Fossil
Crystal System
Trigonal (Cryptocrystalline microfibrous quartz structure)
Mineral Group
Silicates (Subgroup: Tectosilicates)
Chemical Formula
SiO2 (Silicon Dioxide) with trace amounts of carbon, iron oxides, and other mineral impurities
Formation Process
Sedimentary permineralization, where organic material in buried wood is slowly replaced by minerals (primarily silica) over millions of years under anaerobic conditions.
About This Crystal
An irregularly shaped, chunky specimen showing characteristic wood grain patterns and growth rings. The color palette includes earthy tones of beige, cream, greyish-blue, and warm amber-brown, with darker streaks and patches. The luster ranges from vitreous to waxy, and the transparency is semi-translucent to opaque.
Physical Characteristics
Colors range from white and grey to brown, yellow, and black due to iron and manganese oxides. Streak is white. Cleavage is none, fracture is conchoidal to uneven. Specific gravity is approximately 2.60 to 2.68. Tenacity is brittle.
Optical Properties
Refractive index ranges from 1.530 to 1.540. It is aggregate microcrystalline, appearing doubly refractive under polarized light with a low birefringence.
Hardness & Durability
Origin Region
Found globally; notable deposits include Arizona (USA), Madagascar, Argentina, and various locations in Europe and Asia. Forms in sedimentary environments with volcanic ash or mineral-rich groundwater.
Hardness & Durability
Mohs hardness of 6.5 to 7. Good toughness, highly stable and resistant to most chemicals and ordinary wear, making it very suitable for jewelry and decorative objects.
Care & Maintenance
Easy to care for. Clean with warm soapy water and a soft brush. Avoid harsh acids or prolonged exposure to extreme heat. Safe from fading in normal sunlight.
Rarity & Value
Common to uncommon depending on the quality, preservation of wood structure, and presence of colorful mineral inclusions. Value ranges from inexpensive tumbled stones to valuable high-grade display specimens.
Special Characteristics
Retains the original cellular structure of ancient plant material while being completely replaced by stone. May occasionally display chatoyancy or fine color banding.
Lore & History
Historically used in carvings and talismans. In modern crystal healing, it is associated with grounding, patience, stability, and connection to nature, linked primarily to the root chakra.