Only friends get stones (5)
I believe the answer is:
opals
'stones' is the definition.
(I've seen this before)
'only friends' is the wordplay.
'only' becomes 'o' (this might be a standard abbreviation I've not previously seen).
'friends' becomes 'pals' (pal is a kind of friend).
'o'+'pals'='OPALS'
'get' acts as a link.
Can you help me to learn more?
(Other definitions for opals that I've seen before include "Milky white and coloured gems" , "Translucent gemstones" , "Semi-precious stones of milky or bluish colour" , "Milky-white stones" , "Milky gemstones with delicate colours" .)