catlinite vs terracotta

catlinite

noun
  • A red clay from the Upper Missouri region, used by the natives for their pipes. 

terracotta

noun
  • A hard red-brown unglazed earthenware, used for pottery and building construction. 

  • A reddish brown colour, like that of terra cotta. 

adj
  • Of the colour of terracotta. 

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