Difference between Encrustation and Crust

Encrustation

Part of speech: noun

Definition: An incrustation

Crust

Part of speech: noun

Definition: A more solid, dense or hard layer on a surface or boundary.The external layer of most types of bread.The outermost layer of the lithosphere of the Earth. Thickness ranges between 15-35 km.Nerve, gall.

Part of speech: verb

Definition: To cover with a crust.To form a crust.

Example sentence: Cities are 2% of the earth's crust, but they are 50% of the world's population.