We report on the production of nanodiamonds (NDs) with 70-80 nm size via bead assisted sonic disintegration (BASD) of a polycrystalline chemical vapor deposition (CVD) film. The NDs display high crystalline quality as well as intense narrowband (7 nm) room temperature luminescence at 738 nm due to in situ incorporated silicon vacancy (SiV) centers. The fluorescence properties at room and cryogenic temperatures indicate that the NDs are, depending on preparation, applicable as single photon sources or as fluorescence labels.