masterwork vs treasure

masterwork

noun
  • A piece of quality, indicative of having been made by a master; a masterpiece. 

  • A piece done to prove possession of skill sufficient to be ranked a master. 

treasure

noun
  • Anything greatly valued. 

  • A term of endearment. 

  • A collection of valuable things; accumulated wealth; a stock of money, jewels, etc. 

verb
  • To store or stow in a safe place. 

  • To consider to be precious; to value highly. 

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