The Bureau of Mines compared the effects of surface-active chemicals with those of pure water on core-drilling rock and quartz and on fracturing quartz. The objectives were to determine if these chemicals assist drilling and fracturing rock and if zeta potential control was worth pursuing as an aid to full-scale drilling. All tests were performed in the laboratory. No significant increases in drilling rates were observed for 1 to 10,000 ppm al (as alcl3) in flushing water when drilling microline or serpentine, nor for 1 to 10,000 ppm mg (as mgcl2) when drilling microline or marble. Concentrations near those giving a zero zeta potential were used with microline and marble. A 50-pct rate increase was observed for drilling quartz in 0.7 Ppm oleylammonium acetate, which gave a zero zeta potential. No other concentrations were used. No effect on the tensile strength of quartz thread in the 0.05 Ppm al (as alcl3), which gave a zero zeta potential, was observed. Heptanol, reported to give a zero zeta potential on quartz, did not reduce the bending strength of small quartz bars below that in water. These generally negative findings raise doubt about the usefulness of zeta potential control in full-scale drilling.