fossil

Fossiliferous shale or slate with plant impressions

Carbonaceous mudstone/shale; possible fossil plant material (often fern-like impressions)

AI-generated identification · may be incorrect

Dark gray, fine-grained, and weakly lustrous with abundant pale, branching or frond-like surface impressions. Likely hardness 2–4 if shale, or 3–5.5 if metamorphosed to slate; cleavage may be thin and planar.

Identified August 16, 2026More fossil →

Explore Fossiliferous shale or slate with plant impressions in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed from fine mud deposited in a quiet lake, floodplain, or marine basin, later compacted and possibly lightly metamorphosed. The impressions likely record fossilized plants or organic structures, commonly Paleozoic to Mesozoic in age, though the image cannot establish a precise age.

Uses & applications

Primarily a teaching and collecting specimen; fossiliferous shale may be used ornamentally, while slate can serve as roofing or paving stone if sufficiently sound.

Geological facts

The repeated patterns resemble fossil foliage, but weathering, mineral veins, or rock fabric can mimic plant fossils; confirmation requires close inspection of relief, symmetry, and bedding.

Field identification & locations

Look for thin bedding, consistent carbon-rich outlines, and fossil relief that crosses rather than follows random fractures. Common comparable material occurs in coal-bearing sedimentary basins worldwide; avoid acid or aggressive cleaning.