The spectroscopic characteristics of chromium-doped gahnite glass ceramics have been evaluated. The material exhibits multi-site spectra, including a complicated emission spectrum and room temperature anti-Stokes emission. Careful analysis of the room and low temperature spectra, supported by luminescence decay measurements, proves the existence of a t least two high-field sites associated with single Cr3+ ions and pairs of Cr3+ ions. The R line of the highest field sites is accompanied by phonon side bands. Estimates of the associated phonon energies have also been made.