bijou vs billfold

bijou

noun
  • A piece of jewelry; a trinket. 

  • A jewel. 

  • A small intricate piece of metalwork. 

adj
  • small, little (often implying affection) 

  • intricate; finely made 

  • small and elegant 

billfold

noun
  • A small, folding sleeve or case designed to hold paper currency, as well as credit cards, pictures, etc. 

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