Bimineralic, polycrystalline rocksalt specimens ranging in composition from pure halite to pure anhydrite have been fabricated in hydrostatic compression at 150 MPa and 100¿C for 15 minutes. Resulting porosities of the compacted samples increased with increasing anhydrite content, ranging from .02 for pure halite to .14 for pure anhydrite. Twenty-three compacted samples were then deformed in triaxial compression experiments at confining pressures of 10, 100, and 200 MPa, a nominal strain rate of 10-4 sec-1 and a temperature of 200¿C. Sample strength at 10 percent axial strain was directly related to both anhydrite content and pressure. Relatively small strength increases were observed for increases in anhydrite content up to 75 percent, by weight, and for all pressure increases. Much larger increases in strength were observed when the anhydrite content was increased from 75 to 100 percent. Ductilites of less than 10 percent were seen in only two sets of data, the 100 and 75 percent anhydrite samples run at 10 MPa confining pressure, and these data indicated a trend of increasing ductility with increasing halite content and/or confining pressure. All samples exhibited strain hardening except for the 75 percent halite samples at all three pressures and the 50 percent sample of 10 MPa, which exhibited slight strain softening.