igneous vs impetuous

igneous

adj
  • Pertaining to or having the nature of fire; containing fire; resembling fire. 

  • Resulting from, or produced by, great heat. With rocks, it could also mean formed from lava or magma. 

impetuous

adj
  • Characterized by sudden violence or vehemence. 

  • Making arbitrary decisions, especially in an impulsive and forceful manner. 

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