Turn round, love, and you’ll see it’s iridescent (4)
I believe the answer is:
opal
'you'll see it's iridescent' is the definition.
I can't tell whether this definition defines the answer.
'turn round love' is the wordplay.
'turn' shows that the letters should be reversed in order.
'round' becomes 'lap' (as in a round or lap of a park).
'love' becomes 'o' (love means zero in tennis).
'lap'+'o'='lapo'
'lapo' written backwards gives 'OPAL'.
'and' acts as a link.
Can you help me to learn more?
(Other definitions for opal that I've seen before include "Delicately coloured gem" , "Type of gem" , "Glassy gemstone" , "Something milky-white" , "Semi-precious stone of b;uish white colour" .)