Petrified Wood / Fossil Wood Fragment
Incertae sedis; likely Araucarioxylon aff. arizonicum or similar gymnosperm • Body fossil; Petrified/Permineralized plant material
Geological Period
Likely Triassic to Jurassic
Estimated Age
150 - 250 million years
Preservation Type
Permineralization; primarily silicified (chert or jasper replacement of organic cells)
Condition Assessment
Fair; the specimen is a weathered fragment without distinct terminal ends or high-definition cellular structure preserved on the exterior
Taxonomic Classification
Kingdom: Plantae, Division: Spermatophyta (Unranked Gymnospermae)
Morphological Description
Small, weathered fragment exhibiting rough longitudinal striations indicative of wood grain and vascular tissue. Surface shows distinct red-to-tan coloration due to iron oxide staining. Visible layering suggests bark or internal growth rings that have been heavily eroded.
Rock Matrix
Iron-rich sandstone or mudstone remnants; the specimen is largely its own mineralized matrix (silica with limonite/hematite staining)
Formation & Location
Likely Chinle Formation (Arizona, USA) or similar Mesozoic sedimentary deposits in the Colorado Plateau region
Size & Dimensions
Approximately 5-8 cm in length; consistent with common small 'float' fragments found in eroded fossil forests
Value & Rarity
Estimated Market Value
$5 - $15 USD
Auction Estimate
$10 - $30 USD (usually sold in bulk lots or as low-tier single items)
Rarity Assessment
Common; fragments of this quality are abundant in specific geological formations like the Petrified Forest National Park surroundings
Scientific Significance
Provides evidence of ancient forest ecosystems and paleoclimate conditions; helps map the distribution of Mesozoic flora and regional sedimentation patterns
Preparation Recommendations
Requires minimal preparation; cleaning with a soft brush and water is sufficient. Can be hand-polished or tumbled to reveal internal color and grain morphology
Notable Features
Distinctive 'rainbow' coloring from iron oxidation; shows a sharp transition between the darker inner mineralized wood and the lighter, more oxidized outer surface.