solemn vs stony-faced

solemn

adj
  • Inspiring serious feelings or thoughts; sombrely impressive. 

  • Characterized by or performed with appropriate or great ceremony or formality. 

  • Of or pertaining to religious ceremonies and rites; (generally) religious in nature; sacred. 

  • Deeply serious and sombre; grave. 

stony-faced

adj
  • Showing no (or little) expression of emotion; poker-faced. 

How often have the words solemn and stony-faced occurred in a corpus of books? (source: Google Ngram Viewer )