caramel vs rock candy

caramel

noun
  • A smooth, chewy, sticky confection made by heating sugar and other ingredients until the sugars polymerize and become sticky. 

  • A yellow-brown color, like that of caramel. 

  • A (sometimes hardened) piece of this confection. 

adj
  • Of a yellow-brown color. 

rock candy

noun
  • A form of confectionery made by crystallizing sugar around a string. 

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