Stable diamagnetic levitation of masses in excess of one gram has been accomplished in entirely passive systems using pyrolytic graphite and permanent magnets. Analytical and experimental data are given on two vertical thrust bearing assemblies. Extremely low frictional losses were determined from the rate of rotor deceleration in vacuum. Dissipation in a 4 cm diam rotor at 100 rpm was in the nanowatt range. Parametric studies are presented and possible applications discussed.