Petrified wood is a fossil formed when organic plant matter is buried under sediment and replaced by silica through permineralization. Collectors look for well-preserved growth rings, bark texture, and vibrant colors caused by mineral impurities like iron and manganese.
Is this petrified 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 petrified wood with a known reference. Petrified Wood sits at Mohs 6.5-7 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Petrified Wood leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Petrified Wood typically shows a vitreous to waxy luster.
- 4Match the color rangeCompare against the expected color range: brown, red, yellow, black, white.
- 5Look at form & habitTypical habit: pseudomorphous after wood structure.
Often confused with
Petrified Wood vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Luster reads vitreous to waxy on Petrified Wood and waxy on Chalcedony.
How to tell apart: Luster reads vitreous to waxy on Petrified Wood and waxy on Jasper.
How to tell apart: Luster reads vitreous to waxy on Petrified Wood and waxy on Agate.
Often found alongside petrified wood
Minerals reported to co-occur with petrified wood. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- SiO₂
- Mohs hardness
- 6.5-7
- Density
- 2.6-2.7 g/cm³
- Streak
- White
- Luster
- Vitreous to Waxy
- Transparency
- Opaque
- Crystal habit
- Pseudomorphous After Wood Structure
- Cleavage
- None
- Rarity
- Common
- Uses
- Lapidary, Collector, Decorative
- Host rock
- Sedimentary Strata
- Typical price
- $5-50 thumbnail, $50-500 cabinet specimen
Where rockhounds find petrified wood
163 mapped spotsClassic worldwide localities
- Petrified Forest National Park, Arizona, USA
- Madagascar
- Argentina
- Greece
- Indonesia
U.S. states with petrified wood
Each link opens a state-specific list of mapped rockhounding spots that produce petrified wood.
- Washington12 spots
- Oregon11 spots
- Utah11 spots
- Nebraska10 spots
- Texas10 spots
- Pennsylvania9 spots
- California8 spots
- Kansas8 spots
Field-hunting tip
Look in sedimentary strata country — that is the host setting where petrified wood typically forms. If you start seeing quartz, chalcedony, goethite in float, you are in the right ground. Field specimens usually show a pseudomorphous after wood structure habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Washington, Oregon, Utah — start trip planning there.
Common questions
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Find petrified wood on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
