emerald vs nephrite

emerald

noun
  • Any of various green gemstones, especially a green transparent form of beryl, highly valued as a precious stone. 

  • Emerald green, a colour. 

  • Any hummingbird in the genera Chlorostilbon and Elvira; and some in the genus Amazilia 

  • Any of various species of dragonfly of the family Corduliidae. 

adj
  • Of a rich green colour. 

verb
  • To ornament with, or as if with, emeralds; to make green. 

nephrite

noun
  • A semi-precious stone, one of the two types of stone commonly referred to as jade (the other being jadeite). 

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