fossil

Likely petrified wood or silicified fossil fragment

Silicified wood; predominantly microcrystalline quartz (SiO₂)

AI-generated identification · may be incorrect

The fragment appears tan to gray with a dark bluish-black central area and a pale, possibly translucent edge; visible layered or fibrous texture may represent wood grain. Quartz-rich silicified material is typically Mohs 6.5–7, has vitreous to waxy luster, no obvious cleavage, and specific gravity near 2.6.

Identified August 11, 2026More fossil →

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Physical properties

Formation & geological history

Silica-bearing groundwater gradually replaced organic wood tissue during burial, commonly in volcanic ash or sedimentary environments; ages range from millions to hundreds of millions of years. Identification is uncertain from the photograph because diagnostic cellular structure is not clearly visible.

Uses & applications

Used as a lapidary, display, cabochon, or fossil-collection material; it has little industrial value as a small fragment.

Geological facts

Silicified wood can preserve growth rings and microscopic cell walls in quartz. Dark coloration may result from manganese, carbon, iron, or other mineral impurities.

Field identification & locations

Look for recognizable wood grain, concentric growth rings, cellular pattern, quartz-like hardness, and inability to scratch with a steel knife; a streak or microscope examination can help distinguish it from ordinary chert. Common worldwide, especially in volcanic-ash-bearing basins and locations such as Arizona, Indonesia, and Australia.