A mixture of methanol and ethanol in a 4:1 volume ratio has good physical properties for use in these devices. William Bassett invented a “hydrothermal” type of these devices for use with fluids. Conditions in these devices are usually analyzed either with X-ray diffraction on a material whose equation of state is known, or by measuring shifts in the fluorescence lines of ruby. A now-retracted 2020 Nature paper claimed to use these devices to achieve room-temperature superconductivity (15[1]-5[1])in a carbonaceous sulfur hydride. In these devices, a tungsten or rhenium (*) gasket encloses the sample, which must be smaller than a few hundred microns, since these devices create a very small area to transmit a large force. For 10 points, what devices generate millions of atmospheres of pressure by squeezing a sample between two minerals with Mohs hardness 10? ■END■ (0[1])