lava vs ore

lava

noun
  • The molten rock ejected by a volcano from its crater or fissured sides. 

  • Magma. 

  • A shade of red, named after the volcanic lava. 

ore

noun
  • Rock or other material that contains valuable or utilitarian materials; primarily a rock containing metals or gems for which it is typically mined and processed. 

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