Temperature changes caused by small rapid pressure changes have been measured for quartzite, single-crystal quartz, and fluorite to 36 kbar. The Gr¿neisen parameter was then calculated from the adiabatic pressure derivative of temperature (∂T/∂P)s by use of the thermodynamic relationship &ggr; = Ks/T (∂T/∂P)s where Ks is the adiabatic bulk modulus. The measurements were carried out in a piston cylinder apparatus using alcohol as a pressure transmitter. Parameter &ggr; for quartz and quartzite slightly decreases with pressure, whereas we note a large decrease in &ggr; for fluorite with pressure. We find values for q = -(∂ ln &ggr;/∂ ln V)T of 2.0, 1.7, and 4.6 for quartz, quartzite, and fluorite, respectively.