Smooth and white
I believe the answer is:
alabaster
'smooth and white' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for alabaster that I've seen before include "White or translucent mineral" , "White translucent form of gypsum used for statues, vases etc" , "Carved form of gypsum" , "statue material" , "Altar base (anagr.)" .)