| Particle Size | Sediment | Rock |
|---|---|---|
| Coarse-Grained | Gravel | |
| Larger than 256 mm | Boulder | |
| 256–64 mm | Cobble | Conglomerate |
| 64–2 mm | Pebble | |
| Medium-Grained | ||
| 2–0.062 mm | Sand | Sandstone |
| Fine-Grained | Mud | |
| 0.062–0.0039 mm | Silt | Siltstone |
| Mudstone (blocky fracture) | ||
| Finer than 0.0039 mm | Clay | Shale (breaks along bedding) |
| Claystone |