| Material | Dielectric Constant |
| Sand (dry) | 3 - 6 |
| Sand (saturated) | 20 - 30 |
| Silts | 5 - 30 |
| Shales | 5 - 15 |
| Clays | 5 - 40 |
| Humid soil | 30 |
| Cultivated soil | 15 |
| Rocky soil | 7 |
| Sandy soil (dry) | 3 |
| Sandy soil (saturated) | 19 |
| Clayey soil (dry) | 2 |
| Clayey soil (saturated) | 15 |
| Sandstone (saturated) | 6 |
| Limestone (dry) | 7 |
| Limestone (saturated) | 4 - 8 |
| Basalt (saturated) | 8 |
| Granite (dry) | 5 |
| Granite (saturated) | 7 |
From: Hubbard, S. S., J. E. Peterson, Jr., E. L. Majer, P. T. Zawislanski, K. H. Williams, J. Roberts, and F. Wobber, Estimation of permeable pathways and water content using tomographic radar data, The Leading Edge, 16, 1623-1628, 1997.
| Last updated on June 3, 1999 by William P. Clement |