Attractive stone circle seen with friend (4)
I believe the answer is:
opal
'attractive stone' is the definition.
'opal' can be an answer for 'stone' (gemstone). I'm unsure of the 'attractive' bit.
'circle seen with friend' is the wordplay.
'circle' becomes 'O' (O is a circle).
'seen with' is a charade indicator (letters next to each other).
'friend' becomes 'pal' (pal can mean a friend).
'o'+'pal'='OPAL'
Can you help me to learn more?
(Other definitions for opal that I've seen before include "often semi-transparent" , "Glassy gemstone" , "Milky white gem" , "Semi-precious stone of milky or bluish colour" , "Gem with delicate colours" .)