Zinc sulphide quantum dots chemically capped with thioglycerol having two different sizes have been synthesized. The particles have a disordered sphalerite structure and are slightly contracted by 1% against the bulk. Small angle X-ray scattering investigations reveal that powders of these nanocrystallites are mass fractals that aggregate via a reaction-limited process to form irregular but rather dense networks with a fractal dimensionality of D-f = 2.7 and 2.1, respectively.