Investigating magneto-optical properties of colloidal nanocrystals (II-VI, IV-VI, and II-III-VI2), magnetic Van der Waals (vdWs) materials, and 3D and 2D perovskite materials, using magneto-photoluminescence (PL), optically detected magnetic resonance (ODMR), microwave modulated-PL (MMPL) in continuous and time-resolved modes to uncover spin polarization, double valleys, anisotropy effects and the existence of magnetic-exciton coupling, continuous/dynamic Rashba, inversion and symmetry breaking, and anharmonicity. The results are corroborated using DFT, k*p, kinetic and spin-related arguments