calcium hydroxide vs malachite

calcium hydroxide

noun
  • A soft, white powder, Ca(OH)₂, obtained by the action of water on calcium oxide; slaked lime. 

malachite

noun
  • A bright green mineral, a basic copper carbonate, Cu₂CO₃(OH)₂; one of the principal ores of copper. 

  • A mild green colour, like that of the mineral. 

adj
  • Of a colour ranging from olive-taupe to a mild to deeply-rich (at times seemingly translucent) green, like that of the mineral which is present on oxidized copper. 

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