Fossilized Wood (Jet or Lignite Coal Fragment)
Indeterminate Gymnosperm or Pteridosperm fragment (cf. Dadoxylon or Sigillaria) • Body fossil; Plant; Carbonized / Permineralized Wood
Geological Period
Likely Carboniferous (Mississippian/Pennsylvanian) to Cretaceous
Estimated Age
66 to 350 million years
Preservation Type
Carbonization (Coalification) with potential minor permineralization
Condition Assessment
Fair; fragmentary and weathered, lacking specific diagnostic botanical features like bark or branch nodes.
Taxonomic Classification
Kingdom: Plantae; Tracheophyta (Vascular Plants)
Morphological Description
Small, angular fragment with black, vitreous to dull luster. Visible longitudinal grain patterns and cellular striations consistent with secondary xylem structures. Fractures are conchoidal to sub-conchoidal, indicating high carbon concentration.
Rock Matrix
Associated with coal-bearing shale or mudstone; specimen is essentially free of host matrix.
Formation & Location
Possible formations include the Appalachian Basin (USA), Yorkshire coast (UK - Whitby Jet), or similar coal-bearing strata worldwide.
Size & Dimensions
Approximately 2.5 cm x 1.5 cm; small fragment compared to typical trunk or branch fossil sizes.
Value & Rarity
Estimated Market Value
$1 - $5 USD
Auction Estimate
N/A (Typically sold in bulk lots or as a minor curiosity)
Rarity Assessment
Common; high-carbon wood fragments are abundant in most coal-producing geological regions.
Scientific Significance
Provides evidence of local paleobotanical biomass and carbon sequestration processes within an ancient swamp or forest ecosystem.
Preparation Recommendations
Requires minimal preparation; keep dry and avoid handling with oils. Can be polished to reveal grain or stored in a standard specimen box.
Notable Features
High luster and dark coloration suggestive of high-grade coalification, often mistaken for obsidian or slag by amateur collectors.