Contents Page Table 21 1. Electrical resistivity of rocks and soils 304 2.1. Electrical resistivity of mineralized rocks 307 2.2. Electrical resistivity of specular hematite in quartz porphyry 307 3. Electrical resistivity of metallic sulfides 308 4. Electrical resistivity of some oxides and miscellaneous minerals 311 5. Electrical resistivity of hydrocarbons 313 6.1. Electrical resistivity of natural water 314 6.2. Electrical resistivity of saline waters 314 6.3. Effect of water and oil on direct current resistance of sandstone 315 6.4. Electrical resistivity of wet sand 315 6.5. Resistivity of soils and sea water measured with high-frequency alternating current 316 7. Dielectric constant of rocks 317 8. Dielectric constant of minerals 318 8.1. Dielectric constant of Rochelle salt, as function of temperature 318 ELECTRICAL RESISTIVITY (1) Electrolytic conductors .—The electrical conductivity of rocks and soils in place is generally due almost entirely to the moisture content. With some exceptions, the solid minerals which constitute the rock or soil are good insulators. Thus, the conductivity is not an essential property of the rock or rock type; it depends not only upon the capacity of the rock to absorb water and upon the kind and structure of its pore spaces, but also upon the amount and composition of the water retained. Hence, the conductivity may depend to an important extent upon the accident of the geological and climatic environment in which the material happens to find itself. It follows that resistivities tabulated in the literature should not be used to predict the . . .