  An electron spin resonance (ESR) and photoluminescence signal is observed in
the as grown single crystal of stishovite indicating the presence of defects in
the non-irradiated sample. Photoluminescence of the as received stishovite
single crystals exhibits two main bands - a blue at 3 eV and an UV at 4.75 eV.
Luminescence is excited in the range of optical transparency of stishovite
(below 8.75 eV) and, therefore, is ascribed to defects. A wide range of decay
kinetics under a pulsed excitation is observed. For the blue band besides the
exponential decay with a time constant of about 18 {\mu}s an additional ms
component is revealed. For the UV band besides the fast component with a time
constant of 1-3 ns a component with a decay in tens {\mu}s is obtained. The
main components (18 {\mu}s and 1-3 ns) possess a typical intra-center
transition intensity thermal quenching. The effect of the additional slow
component is related to the presence of OH groups and/or carbon molecular
defects modifying the luminescence center. The additional slow components
exhibit wave-like thermal dependences. Photo-thermally stimulated
creation-destruction of complex comprising host defect - interstitial modifiers
explains slow luminescence wave-like thermal dependences.
