cameo vs locket

cameo

noun
  • A piece of jewelry, etc., carved in relief. 

  • A single very brief appearance, especially by a prominent celebrity in a movie or song. 

verb
  • To appear in a cameo role. 

locket

noun
  • A pendant that opens to reveal a space used for storing a photograph or other small item. 

  • A small white marking on a cat's coat. 

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