The fabrication of Ge-doped light-emitting devices in single-crystal α-quartz without destroying its crystal structure via the dynamic solid phase epitaxial regrowth technique is being pursued. This paper presents results on the cathodoluminescence (CL) after 120 keV Ge implantation in α-quartz at 1173 K with fluences between 1 × 1014 and 1 × 1016 ions/cm2. Rutherford backscattering-channeling analysis showed that the Ge implantation up to 4 × 1014 ions/cm2 produced isolated damage zones. The transition to an amorphous layer is accompanied by a strong increase in the CL output. The CL spectra taken at 10-300 K show six bands located at 260 nm (4.9 eV, UV), 288 nm (4.3 eV, UV), 383 nm (3.1 eV, violet), 453 nm (2.7 eV, blue), 511 nm (2.4 eV, green) and 620 nm (2.0 eV, red). Only the violet band is associated with the Ge-related defects or the formation of Ge-clusters; it reaches its maximum intensity at 7 × 1014 Ge-ions/cm 2. All the other bands are connected to various defect centers in the SiO2 network. © 2003 Elsevier B.V. All rights reserved.