Chemically guided solid phase epitaxy of α-quartz after Rb +-ion implantation and thermal annealing in 18O 2 was studied in order to clarify the role of the alkali ions and oxygen during this process. In particular, the influence of the 18O2 gas pressure and Rb+-ion fluence was investigated via Rutherford Backscattering Channeling and Time-of-Flight Elastic Recoil Detection techniques. Complete or partial epitaxy was observed, depending on the Rb-fluence, annealing temperature, and oxygen pressure. The recrystallization rate increased with increasing ion fluence, while the oxygen pressure had only little influence on the recovery process. Among these three parameters, the annealing temperature plays the most important role. © 2003 Elsevier B.V. All rights reserved.