| Type | Resistivity (Ohm metre) |
| Sea water | 0.1 - 1 |
| Garden soil/alluvial clay | 5 - 50 |
| Clay | 5 - 100 |
| Clay, sand and gravel | 40 - 250 |
| Porous chalk | 30 - 100 |
| Quartzite/crystalline limestone | 300+ |
| Rock | 1000 - 10,000 |
| Gneiss/igneous rock | 2000+ |
| Dry concrete | 2000 - 10,000 |
| Wet concrete | 30 - 100 |
| Ice | 10,000 - 100,000 |