Hand-held firework (8)
I believe the answer is:
sparkler
'hand-held firework' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sparkler that I've seen before include "Eg, a diamond" , "Jewel" , "Slow-burning firework and a diamond" , "Bright gem" , "Possibly brilliant" .)