From the results including time-resolved pH measurements, visual observations, and cryo-TEM imaging, we correlated information about the morphology and structure of the transitional nanophases with the specific moments in time. However, such ex-situ quenching approach is limited by the realistically achievable time resolution and the number of samples that can be analyzed with electron microscopy. To gain more insights into the as-observed crystallization pathways, we wanted to simultaneously correlate the in-situ morphological information, with the temporal phase composition and reaction kinetics. This was achieved by using in-situ approaches, avoiding any potential artifacts e.g. from quenching. Therefore, insitu scattering (combined SAXS and WAXS) and pH measurements were performed to follow crystallization (see Methods: In-situ SAXS/WAXS). In this way, global information about the occurrence of crystalline phases, the presence and size of agglomerates with their building units could be quantified. Based on the occurrence of diffraction reflections in the pure Ni-system (Figure , B), Nistruvite precipitates rapidly for t < 100 s as the sole crystalline phase. In the low-q region, at t < 100 s after the injection of the metal-bearing solution, the scattering signal is dominated by a high intensity scattering pattern, which implies the presence of large particles of the Nistruvite crystals manifesting themselves merely as a q -4 intensity dependence (Porod interface). In contrast, Co phosphate octahydrate precipitated much slower at t > 600 s, while characteristic signal from the primary building units and their agglomerates was visible in the SAXS for q < 1 nm -1 (Figure ). Here, a so-called "knee"-region can be identified with its centroid at around 0.4 nm -1 indicating potentially polydisperse form factors of nucleating entities with different sizes (marked with arrow in Figure ). The precipitation of the actual crystals was completed only at t > 1500 s, evidenced by reaching an equilibrium pH of 4.7, the reduction of scattering intensity between 0.3 -5 nm -1 and the development of a Porod interface.