Part showing ten gems scattered (7)
I believe the answer is:
segment
'part' is the definition.
(I know that segment is a more specific form of the action part)
'ten gems scattered' is the wordplay.
'scattered' indicates an anagram.
'ten'+'gems'='tengems'
'tengems' is an anagram of 'SEGMENT'.
'showing' acts as a link.
(Other definitions for segment that I've seen before include "Portion" , "(Divided-up) part" , "split up" , "Section of a circle" , "Part of a circle cut off by a chord" .)