in·crust·a·tion 
(ĭn′krŭ-stāshən) also en·crust·a·tion (ĕn′-)
(ĭn′krŭ-stāshən) also en·crust·a·tion (ĕn′-)n.
1.
a. The act of encrusting.
b. The state of being encrusted.
2. A crust or coating: an incrustation of salt on the window.
3.
a. A decorative technique in which a contrasting material is applied to a surface as an inlay or overlay.
b. A material so applied.
4. Biology A coating of hardened exudate or other material on a body or body part; a scale or scab.