Not any nut tree rising for Clay? (6)
I believe the answer is:
kaolin
'clay?' is the definition.
(I've seen this before)
'not any nut tree rising' is the wordplay.
'not any' becomes 'nil' (I've seen this in another clue).
'nut tree' becomes 'oak' (I can't justify this - if you can you should believe this answer much more).
'rising' is a reversal indicator (going up in a down clue).
'nil'+'oak'='niloak'
'niloak' backwards is 'KAOLIN'.
'for' is the link.
Can you help me to learn more?
(Other definitions for kaolin that I've seen before include "Nil oak in the ceramic clay" , "Soft white clay, used for making fine porcelain, say" , "China clay" .)