melanoid vs onyx

melanoid

adj
  • Relating to, or afflicted with, melanosis. 

  • Relating to, or resembling, melanin. 

noun
  • Synonym of melanoidin 

onyx

adj
  • jet-black 

noun
  • A jet-black color, named after the gemstone. 

  • Any of various lycaenid butterflies of the genus Horaga. 

  • A banded variety of chalcedony, a cryptocrystalline form of quartz. 

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