beryl vs ultramarine

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. 

ultramarine

noun
  • A brilliant dark blue or slightly purplish colour like that of the pigment. 

  • In full ultramarine blue: a brilliant blue pigment that was traditionally made from ground-up lapis lazuli, and now usually either extracted from mineral deposits or made synthetically. 

adj
  • Of a brilliant dark blue or slightly purplish colour like that of the pigment (noun sense 1). 

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