Silicified lignite is a form of petrified wood where the organic plant structure has been replaced by microcrystalline quartz. Collectors often look for visible tree ring patterns or bark texture preserved within the chalcedony matrix. It is highly valued in lapidary for its ability to take a high polish and its varied, intricate patterns.
Is this silicified lignite?
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 silicified lignite with a known reference. Silicified Lignite 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: Wood.
- 3Check the preservationPreservation: Silicified. 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, black, gray, tan, red, yellow.
Often confused with
Silicified Lignite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads vitreous on Silicified Lignite and waxy on Agate.
How to tell apart: Luster reads vitreous on Silicified Lignite and waxy on Jasper.
How to tell apart: Luster reads vitreous on Silicified Lignite and waxy on Chert.
Often found alongside silicified lignite
Minerals reported to co-occur with silicified lignite. 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
- Translucent
- Rarity
- Common
- Uses
- Lapidary, Collector, Decorative
- Host rock
- sedimentary
- Organism
- Wood
- Preservation
- Silicified
Where rockhounds find silicified lignite
1 mapped spotsClassic worldwide localities
- Petrified Forest National Park, USA
- Arizona, USA
- Madagascar
- Argentina
- Greece
Field-hunting tip
Where it forms: sedimentary. 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 Nevada. Start trip planning there.
More silicified lignite photos
Common questions
How do you identify silicified lignite?+
Where is silicified lignite found?+
Can I find silicified lignite in the United States?+
What rocks look like silicified lignite?+
What minerals are found with silicified lignite?+
What kind of rock does silicified lignite form in?+
What is silicified lignite used for?+
Find silicified lignite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
