Strange colpitt's oscillator(s)
simulate this circuit &ndash; Schematic created using CircuitLab

Draw the circulating currents. 

There is a tight energy storage loop, at the collect/VDD.

There is a large circulating loop, being the 0.033 at VDD_to_GND, then the 0.033 across the emitter resistor, then then 680pF across emitter-collector.
Thus the losses of these 3 capacitors helps set the QualityFactor of this oscillator.