encrustation vs decoration

encrustation and decoration both are nouns.

Word	Noun	Adjective	Verb	Adverb
encrustation	Yes	No	No	No
decoration	Yes	No	No	No

As nouns, decoration is a hypernym of encrustation; that is, decoration is a word with a broader meaning than encrustation:

encrustation: a decorative coating of contrasting material that is applied to a surface as an inlay or overlay
decoration: something used to beautify

Other hypernyms of encrustation include ornament, ornamentation.

encrustation (noun)	decoration (noun)
a decorative coating of contrasting material that is applied to a surface as an inlay or overlay	the act of decorating something (in the hope of making it more attractive)
a hard outer layer that covers something	something used to beautify
the formation of a crust	an award for winning a championship or commemorating some other event