calculus vs concretion

calculus

noun
  • A stony concretion that forms in a bodily organ. 

  • Differential calculus and integral calculus considered as a single subject; analysis. 

  • Deposits of calcium phosphate salts on teeth. 

  • Any formal system in which symbolic expressions are manipulated according to fixed rules. 

  • A decision-making method, especially one appropriate for a specialised realm. 

concretion

noun
  • A rounded mass of a mineral, sometimes found in sedimentary rock or on the ocean floor. 

  • The action of making something concrete or the result of such an action. 

  • A solid, hard mass formed by a process of aggregation or coalescence. 

  • The process of aggregating or coalescing into a mass. 

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