High-flyer's piece of jewellery changes hands (6)
I believe the answer is:
rocket
'high-flyer's' is the definition.
(rockets fly high in the air)
I can't explain the remainder of the clue.
(Other definitions for rocket that I've seen before include "It's propelled to a great height by combustion" , "Firework and salad ingredient" , "Aerial projectile" , "Soar" , "Severe reprimand" .)