encrustment

encrustment

or

incrustment

n
an outer layer of crust
References in periodicals archive ?
Spawning aggregations of sheepshead are clustered around just about every coastal structure that's hard enough to sport an encrustment of barnacles and oysters.
1999) included soft shell (shell soft and pliable), new hard shell (firm to hard shell that lacked wear or encrustment), old shell (wear and encrustment present) and very old shell (extensive signs of shell wear and encrustment).