Novel Na₃Li₃Sc₂F₁₂ microcrystals with cubic-phase structure, (110)-truncated cubooctahedral morphologies, as well as self-activated white-light luminescence are reported for the first time. Doping of this cubic polymorph with optically active lanthanide ions or ion-pairs illustrates its suitability as a host lattice for the UC/DC luminescence, which opens a window of additional hosts for further fundamental research and various applications.