Stone from old friend (4)
I believe the answer is:
opal
'stone' is the definition.
(gemstone)
'old friend' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'friend' becomes 'pal' (pal can mean a friend).
'o'+'pal'='OPAL'
'from' is the link.
(Other definitions for opal that I've seen before include "One in a ring perhaps" , "Iridescent gemstone" , "One's stony" , "Precious stone" , "Milky-white mineral" .)