Increased share, like a gem (4,3)
I believe the answer is:
rose cut
'like a gem' is the definition.
I can't tell whether this defines the answer.
'increased share' is the wordplay.
'increased' becomes 'rose' (rise can mean to increase or go up).
'share' becomes 'cut' (cut is a kind of share).
'rose'+'cut'='ROSE-CUT'
Can you help me to learn more?
(Other definitions for rose cut that I've seen before include "Diamond in this form" , "Like some gemstones" , "Multi-faceted" .)