Mineral makes fashionista evenly little (7)
I believe the answer is:
diorite
'mineral' is the definition.
The definition and answer can be both substances as well as being singular nouns.
Maybe there's a link between them I don't understand?
'fashionista evenly little' is the wordplay.
'fashionista' becomes 'dior' (I can't explain this - if you can you should believe this answer much more).
'evenly' indicates alternate letters (the letters in even-numbered positions).
The alternating letters of 'little' are 'ite'.
'dior'+'ite'='DIORITE'
'makes' is the link.
Can you help me to learn more?
(Another definition for diorite that I've seen is " Coarse-grained igneous rock".)