granite vs inflexible

granite

noun
  • A group of igneous and plutonic rocks composed primarily of feldspar and quartz. Usually contains one or more dark minerals, which may be mica, pyroxene, or amphibole. Granite is quarried for building stone, road gravel, decorative stone, and tombstones. Common colors are gray, white, pink, and yellow-brown. 

  • Toughness; the quality of having a thick skin or being rough. 

inflexible

adj
  • Not willing to change, e.g. one's opinion or habits. 

  • Not flexible; not capable of bending or being bent. 

  • Not able to be changed or adapted to circumstances. 

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