Related Clues:
- Most common sedimentary rock
- Fine-grained sedimentary rock
- Asphalt trap
- Fine pieces of stone on leash
- Stone that splits easily into fine pieces
- Layered sedimentary rock
- Sedimentary clay rock, which may contain oil
- Preserver of the Ancients — salt and heart of plum?
- Rock often containing quartz
- Good place to hunt fossils
- Oil-rich mineral
- Fossil holder
- Kerosene source
- Fissile rock
- Fracking rock