A silicified pine cone is a fossil in which the cone's original organic material has been replaced by microcrystalline silica, typically chalcedony or agate. Look for well-defined, distinct scales and an overall symmetrical, cone-shaped geometry. It is found in sedimentary layers where mineral-rich groundwater has permeated an ancient forest floor.
Is this silicified pine cone?
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 pine cone with a known reference. Silicified Pine Cone 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: Conifer cones, notably Araucaria mirabilis of the Cerro Cuadrado Petrified Forest, Patagonia. Age: Cerro Cuadrado: Middle Jurassic (about 160 million years ago).
- 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: waxy.
- 5Match the color rangeCompare against the expected color range: brown, tan, gray, white, black.
Often found alongside silicified pine cone
Minerals reported to co-occur with silicified pine cone. 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
- Waxy
- Transparency
- Opaque
- Rarity
- Uncommon
- Uses
- Collector, Lapidary, Decorative
- Host rock
- sedimentary deposits
- Organism
- Conifer cones, notably Araucaria mirabilis of the Cerro Cuadrado Petrified Forest, Patagonia
- Age
- Cerro Cuadrado: Middle Jurassic (about 160 million years ago)
- Preservation
- Silicified
Where rockhounds find silicified pine cone
1 mapped spotsClassic worldwide localities
- Oregon, USA
- Argentina
- Madagascar
- Washington, USA
Field-hunting tip
Where it forms: sedimentary deposits. If you start seeing quartz, chalcedony, agate in float, you are in the right ground. In the U.S., the densest reported localities are in Oregon. Start trip planning there.
More silicified pine cone photos
Common questions
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