chipping vs spall

chipping

noun
  • A fragment broken off a larger material. 

  • The act of breaking something into small fragments, or of removing fragments from pottery etc. 

spall

noun
  • A splinter, fragment or chip, especially of stone. 

verb
  • To break into fragments or small pieces. 

  • To reduce, as irregular blocks of stone, to an approximately level surface by hammering. 

How often have the words chipping and spall occurred in a corpus of books? (source: Google Ngram Viewer )