faience vs potsherd

faience

noun
  • A type of tin-glazed earthenware ceramic. 

  • The beads and small ornaments of the eastern Mediterranean. (Of bronze and iron age manufacture using frit technology.) 

potsherd

noun
  • A piece of ceramic from pottery, often found on an archaeological site. 

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