One who reprimands Mark goes very pale (9)
I believe the answer is:
alabaster
'very pale' is the definition.
'one who reprimands mark goes' is the wordplay.
'one' becomes 'a'.
'who reprimands' becomes 'lambaster'.
'mark' becomes 'm'.
'goes' is a deletion indicator.
'lambaster' with 'm' taken out is 'labaster'.
'a'+'labaster'='ALABASTER'
(Other definitions for alabaster that I've seen before include "White substance" , "medium of sculpture" , "Translucent white gypsum as found carved into ornaments" , "White stone carved into ornaments" , "White ornamental stone" .)