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                        Details                    
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                    Written by: Newton C. Braga    
         
| Material | Min. | Max. | 
| Air | 1 | 1 | 
| Amber | 2.6 | 2.7 | 
| Asbestos fiber | 3.1 | 4.8 | 
| Bakelite | 5 | 22 | 
| Barium Titanate | 100 | 1 250 | 
| 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 | 
| Nylon | 3.4 | 22.4 | 
| Paper | 1.5 | 3 | 
| Paraffin | 2 | 3 | 
| Plexiglass | 2.6 | 3.5 | 
| Polycarbonate | 2.9 | 3.2 | 
| Polyethylene | 2.5 | 2.5 | 
| 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 |