Computer simulation is used to generate microstructures by nucleation on a 3D network of Kelvin polyhedra. The Kelvin polyhedra network was used as a model for a polycrystalline network. Information provided by usual descriptors of microstructural evolution: the volume fraction and mean interfacial area density are perhaps insufficient to fully characterize those microstructures. Therefore, microstructural descriptors that are less often used such as the contiguity, the contiguity ratio, the dispersion parameter and the duplex parameter were tested. These parameters showed to be able to increase the understanding of the microstructural changes for Kelvin polyhedra/grain boundary nucleated transformations. The contiguity and the dispersion parameter were particular useful to provide better understanding of the microstructural evolution studied here.