Something white carved in Arab slate (9)
I believe the answer is:
alabaster
'white carved in arab slate' is the definition.
'alabaster' can be an answer for 'white' (I've seen this before). I am not certain of the 'carved in arab slate' bit.
'something' is the wordplay.
I cannot really understand how this works, but
'something' could be 'er' (I've seen this in other clues) and 'er' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for alabaster that I've seen before include "White substance" , "medium of sculpture" , "Stone often used for carving" , "Arabs tale (anag.)" , "White translucent form of gypsum used for statues, vases etc" .)