fossil

Petrified Wood

Silicified wood (Quartz/Chalcedony replacement)

Hardness: 6.5-7 (Mohs scale), Color: Brown, grey, tan, and reddish-brown due to iron oxides, Luster: Waxy to vitreous on cut surfaces, Structure: Retains cellular structure of the original plant tissue, but composed of cryptocrystalline quartz.

Hardness: 6

Identified July 12, 2026More fossil →

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Physical properties

Formation & geological history

Formed through the process of permineralization, where organic wood material is replaced by minerals (usually silica) from groundwater over millions of years. Most common in Triassic to Paleogene deposits (approx. 200 million to 20 million years old).

Uses & applications

Used for decorative ornaments, furniture (like tabletops), jewelry (cabochons), and as museum or private collector specimens.

Geological facts

This specimen appears to be a cross-section of a larger trunk, showing concentric growth rings and a central pith area. The distinctive texture on the surface is likely due to tool marks from a saw rather than natural crystal growth.

Field identification & locations

Identify by looking for wood-like grain, bark textures, or growth rings in a heavy, cold-to-the-touch stony material. Common in Arizona (USA), Madagascar, and Indonesia.

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