What's That Rock?Shale
A soft sedimentary rock made of compacted mud and clay. It splits into thin layers and crumbles easily.
How to identify Shale
- Splits into thin flakes or plates
- Smells earthy when wet
- Crumbles or scratches with a fingernail or knife
Often confused with
- Slateharder, rings when tapped
- Mudstonebreaks in blocks
- Siltstone
Is Shale valuable?
Common.
What changes the price
- Common rock: low value as a specimen
- Fossil-bearing pieces are valued for the fossil, not the rock
Uses
- Bricks, cement, source of fossils
Care
Fragile and crumbly.
Identifying a stone from a description or a photo is an estimate. Many stones look alike. Ask an expert or a gem lab before you buy, sell or rely on an identification.
Updated October 2026