Art Basel reeling after mag exposed material used in column (9)

I believe the answer is:

alabaster

I'm a little stuck... Click here to teach me more about this clue!

'material used in column' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.

'art basel reeling after mag exposed' is the wordplay.
'reeling' indicates anagramming the letters.
'after' is a charade indicator (letters next to each other).
'exposed' indicates the central letters (the inside of the word is exposed).
The middle letter of 'mag' is 'a'.
'art'+'basel'='artbasel'
'artbasel' is an anagram of 'labaster'.
'labaster' after 'a' is 'ALABASTER'.

Can you help me to learn more?

(Other definitions for alabaster that I've seen before include "Arabs tale (anag.)" , "Type of gypsum" , "Altar base (anagr.)" , "statue material" , "that's smooth and white" .)

I've seen this clue in The Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.