sedimentary
Petrified Wood
Silicified wood (Quartz/Chalcedony/Opal replacing organic matter)
Hardness: 6.5-7 (Mohs scale); Color: Brown, tan, cream, with black banding; Luster: Vitreous to waxy; Crystal structure: Cryptocrystalline (microscopic quartz); Specific gravity: 2.6-2.9.
- Hardness
- 6
- Color
- Brown, tan, cream, with black banding
- Luster
- Vitreous to waxy
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Physical properties
Hardness: 6.5-7 (Mohs scale); Color: Brown, tan, cream, with black banding; Luster: Vitreous to waxy; Crystal structure: Cryptocrystalline (microscopic quartz); Specific gravity: 2.6-2.9.
Formation & geological history
Formed through permineralization where organic remains are replaced by minerals (usually silica) from groundwater while buried in sediment. This specimen likely dates from the Mesozoic or Cenozoic eras.
Uses & applications
Commonly used for lapidary work, jewelry, interior decor (bookends), and as educational fossils in collections.
Geological facts
Unlike regular fossils which are just impressions, petrified wood is a three-dimensional representation of original organic material where cell structures are often preserved in stone.
Field identification & locations
Identify in the field by looking for bark textures, growth rings, or wood-like grain in a heavy, cold stony mass. Common in areas with ancient volcanic ash or river delta deposits.
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