Kind of diamond not reduced in price (5)
I believe the answer is:
uncut
'kind' is the definition.
Both the definition and answer are adjectives. Maybe you can see an association between them that I don't see?
'diamond not reduced in price' is the wordplay.
'diamond not' becomes 'u' (I can't justify this - if you can you should give a lot more credence to this answer).
'reduced' means to remove the first letter.
'price' becomes 'cut price' (cut price is a kind of price).
'in' with its initial letter taken off is 'n'.
'u'+'n'+'cut'='UNCUT'
'of' is the link.
Can you help me to learn more?
(Other definitions for uncut that I've seen before include "Complete, untrimmed" , "(Of a diamond) rough" , "Descriptive of raw diamonds" , "Unexpurgated" , "diamonds, originally" .)