encrustation encrustation /ˌɛnkrʌˈsteɪʃən/

noun

1. A decorative coating of contrasting material that is applied to a surface as an inlay or overlay  ( encrustation , incrustation )
   a decorative coating of contrasting material that is applied to a surface as an inlay or overlay
   
   
2. A hard outer layer that covers something  ( crust , encrustation , incrustation )
   a hard outer layer that covers something
   
3. The formation of a crust  ( encrustation , incrustation )
   the formation of a crust