Stone gets round to friend (4)
I believe the answer is:
opal
'stone' is the definition.
(gemstone)
'round to friend' is the wordplay.
'round' becomes 'o' (round can mean a round object).
'to friend' becomes 'pal' (pal can mean a friend).
'o'+'pal'='OPAL'
'gets' is the link.
(Other definitions for opal that I've seen before include "Opaque gem" , "Translucent gem" , "Gem with delicate colours" , "Type of gemstone" , "Milky white gemstone" .)