incrustations is a form of:

Incrustation



ENGLISH MEANING
noun
1.
The act of incrusting, or the state of being incrusted.
2.
A crust or hard coating of anything upon or within a body, as a deposit of lime, sediment, etc., from water on the inner surface of a steam boiler.
3.
A covering or inlaying of marble, mosaic, etc., attached to the masonry by cramp irons or cement.
4.
Anything inlaid or imbedded.