beryl vs midnight blue

beryl

noun
  • A dull blueish green colour. 

  • An example (a stone) of the mineral beryl. 

  • A mineral of pegmatite deposits, often used as a gemstone. 

adj
  • Of a dull bluish green colour. 

midnight blue

noun
  • a dark blue colour, almost black. 

adj
  • of a dark blue colour, almost black. 

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