encrustation vs formation

encrustation and formation both are nouns.

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

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

encrustation (noun)	formation (noun)
a decorative coating of contrasting material that is applied to a surface as an inlay or overlay	the act of fabricating something in a particular shape
a hard outer layer that covers something	the act of forming or establishing something
the formation of a crust	creation by mental activity
	a particular spatial arrangement
	an arrangement of people or things acting as a unit
	(geology) the geological features of the earth
	natural process that causes something to form