brunet vs obsidian

brunet

adj
  • Of a man or boy, having brown or black hair. 

  • Of a man's or boy's hair: brown or black. 

noun
  • A man or boy with brown or black hair. 

obsidian

adj
  • black 

noun
  • A type of naturally occurring black glass produced by volcanoes. 

  • A slightly bluish black, the color of obsidian glass. 

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