Fossilized wood forms when plant material is buried in sediment and replaced by silica-rich water, preserving the original cellular structure. Collectors look for visible tree rings, bark texture, and vibrant patterns created by mineral impurities during the permineralization process. It is commonly found in ancient riverbeds and volcanic ash deposits where organic decay was halted.
Is this fossilized wood?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch fossilized wood with a known reference. Fossilized Wood sits at Mohs 6.5-7, softer than the next harder reference, harder than the previous one.
- 2Name the organismDecide what left the fossil before worrying about the rock. Organism: Trees and tree-like plants.
- 3Check the preservationPreservation: Cell walls replicated by minerals, mostly silica as opal, chalcedony or quartz. That controls the weight, the hardness and how the piece takes a polish.
- 4Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 5Match the color rangeCompare against the expected color range: brown, red, yellow, white, black, multicolored.
Often confused with
Fossilized Wood vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads vitreous on Fossilized Wood and waxy on Agate.
How to tell apart: Luster reads vitreous on Fossilized Wood and waxy on Jasper.
How to tell apart: Luster reads vitreous on Fossilized Wood and waxy on Chert.
Often found alongside fossilized wood
Minerals reported to co-occur with fossilized wood. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Mohs hardness
- 6.5-7
- Density
- 2.6-2.7 g/cm³
- Luster
- Vitreous
- Transparency
- Opaque
- Rarity
- Common
- Uses
- Lapidary, Collector, Decorative, Jewelry
- Host rock
- sedimentary deposits
- Organism
- Trees and tree-like plants
- Preservation
- Cell walls replicated by minerals, mostly silica as opal, chalcedony or quartz
Where rockhounds find fossilized wood
1 mapped spotsClassic worldwide localities
- Arizona, USA
- Madagascar
- Indonesia
- Argentina
- Greece
Field-hunting tip
Where it forms: sedimentary deposits. If you start seeing quartz, chalcedony, opal in float, you are in the right ground. In the U.S., the densest reported localities are in Indiana. Start trip planning there.
More fossilized wood photos
Common questions
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Find fossilized wood on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
