| 
| Material | Min. | Max. |  
| Air | 1 | 1 |  
| Amber | 2.6 | 2.7 |  
| Asbestos fiber | 3.1 | 4.8 |  
| Bakelite | 5 | 22 |  
| Barium Titanate | 100 | 1250 |  
| Beeswax | 2.4 | 2.8 |  
| Cambric | 4 | 4 |  
| Carbon Tetrachloride | 2.17 | 2.17 |  
| Celluloid | 4 | 4 |  
| Cellulose Acetate | 2.9 | 4.5 |  
| Durite | 4.7 | 5.1 |  
| Ebonite | 2.7 | 2.7 |  
| Epoxy Resin | 3.4 | 3.7 |  
| Ethyl Alcohol | 6.5 | 25 |  
| Fiber | 5 | 5 |  
| Formica | 3.6 | 6 |  
| Glass | 3.8 | 14.5 |  
| Glass Pyrex | 4.6 | 5 |  
| Gutta Percha | 2.4 | 2.6 |  
| Isolantite | 6.1 | 6.1 |  
| Kevlar | 3.5 | 4.5 |  
| Lucite | 2.5 | 2.5 |  
| Mica | 4 | 9 |  
| Micarta | 3.2 | 5.5 |  
| Mycalex | 7.3 | 9.3 |  
| Neoprene | 4 | 6.7 |  | 
| Material | Min. | Max. |  
| Nylon | 3.4 | 22.4 |  
| Paper | 1.5 | 3 |  
| Paraffin | 2 | 3 |  
| Plexiglass | 2.6 | 3.5 |  
| Polycarbonate | 2.9 | 3.2 |  
| Polyethylene | 2.2 | 2.4 |  
| Polyimide | 3.4 | 3.5 |  
| Polystyrene | 2.4 | 3 |  
| Porcelain | 5 | 6.5 |  
| Quartz | 5 | 5 |  
| Rubber | 2 | 4 |  
| Ruby Mica | 5.4 | 5.4 |  
| Selenium | 6 | 6 |  
| Shellac | 2.9 | 3.9 |  
| Silicone | 3.2 | 4.7 |  
| Slate | 7 | 7 |  
| Soil dry | 2.4 | 2.9 |  
| Steatite | 5.2 | 6.3 |  
| Styrofoam | 1.03 | 1.03 |  
| Teflon | 2.1 | 2.1 |  
| Titanium Dioxide | 100 | 100 |  
| Vaseline | 2.16 | 2.16 |  
| Vinylite | 2.7 | 7.5 |  
| Water distilled | 34 | 78 |  
| Waxes, Mineral | 2.2 | 2.3 |  
| Wood dry | 1.4 | 2.9 |  |