Strange oscillator circuit

Discovered this by accident while debugging a design - an odd oscillator configuration.

Not self-starting, but once started will continue oscillating indefinitely. Seems to need a fairly high gain transistor, and is somewhat dependent on coil and transistor type.

Possibly not very useful due to dependence on component characteristics....

It oscillates with R1 from 1 to 5K, and on supplies of 2.5v upwards.

Coil used - 100uH power inductor.