hallmark vs specificality

hallmark

noun
  • A distinguishing characteristic. 

  • An official marking made by a trusted party, usually an assay office, on items made of precious metals. 

verb
  • To provide or stamp with a hallmark. 

specificality

noun
  • specificity 

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