Ugliness of earth that's right next to a mineral (7)
I believe the answer is:
eyesore
'ugliness' is the definition.
(I know that eyesore is a type of ugliness)
'of earth that's right next to a mineral' is the wordplay.
'of earth' becomes 'e' (I can't justify this - if you can you should give a lot more credence to this answer).
'that's right' becomes 'yes' (right can mean yes or okay).
'next to' says to put letters next to each other.
'a mineral' becomes 'ore' (ore is a kind of mineral).
'e'+'yes'+'ore'='EYESORE'
Can you help me to learn more?
(Other definitions for eyesore that I've seen before include "Ugly sight, not nice to see" , "mess" , "Thing that is ugly to look at" , "It's offensively ugly" , "pigsty" .)