fossil

Petrified wood

Silicified wood, commonly quartz/chalcedony (SiO₂) replacing wood tissue

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; brown, gray, gold, and purplish tones with a rough, woody grain and possible cellular texture. Typically vitreous to dull luster, cryptocrystalline quartz structure, and no distinct cleavage.

Identified August 13, 2026More fossil →

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Physical properties

Formation & geological history

Buried wood was gradually mineralized as silica-rich groundwater replaced organic tissue, preserving the original structure; specimens range from Paleozoic to Cenozoic in age. Common in volcanic ash beds, river sediments, and arid regions.

Uses & applications

Used as a decorative stone, paperweight, cabochon material, and collector fossil; larger pieces are cut for furniture, slabs, and sculpture. Value depends strongly on color, preservation, size, and polish.

Geological facts

The image’s irregular woody pattern and mineral coloration are consistent with silicified wood, though a close inspection or hardness test is needed for certainty. Trace iron, manganese, and other minerals produce gold, red, purple, or black colors.

Field identification & locations

Commonly found in Arizona, Utah, Nevada, Indonesia, Madagascar, and Australia. Look for growth rings, bark or cellular patterns, silica-like hardness, and absence of fresh organic fibers; avoid destructive testing on valuable specimens.