Nuclear spin diffusion can be utilized efficiently to gain information on the microscopic homogeneity in disordered solids. Two-dimensional NMR spectroscopy is employed for the measurement of the nuclear spin diffusion. The method is illustrated by comparing 2-dimensional 13C spin diffusion spectra of powder and melt-formed mixts. of adamantane and 2,2,3,3-tetramethylbutane. [on SciFinder (R)]