costume jewellery vs locket

costume jewellery

noun
  • Inexpensive jewellery, made of glass and other non-precious materials. 

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 costume jewellery and locket occurred in a corpus of books? (source: Google Ngram Viewer )