argillaceous vs clayey

argillaceous

adj
  • pertaining to clay; made of, containing, or resembling clay 

clayey

adj
  • Composed of clay or containing (much) clay; clayish. 

  • Resembling clay; claylike, clayish. 

  • Of the human body, as contrasted with the soul; bodily, human, mortal. 

  • Covered or dirtied with clay. 

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