beryl vs virescent

beryl

adj
  • Of a dull bluish green colour. 

noun
  • A dull blueish green colour. 

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

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

virescent

adj
  • Green-like, greenish. 

  • Becoming green. 

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