We present the results of Raman-scattering measurements of diamond (12C) and of cubic boron nitride, and fluorescence measurements of ruby, Sm:yttrium aluminum garnet (Sm:YAG), and SrB4O7:Sm2+ in the diamond anvil cell at high pressures and temperatures. These measurements were accompanied by synchrotron x-ray-diffraction measurements on gold. We have extended the room-temperature calibration of Sm:YAG in a quasihydrostatic regime up to 100 GPa. The ruby scale is found to systematically underestimate pressure at high pressures and temperatures compared with all the other sensors. On this basis, we propose an alternative high-temperature ruby pressure scale that is valid to at least 100 GPa and 850 K.