incrustation (n.)

• blocking
• clouding
• coating
• coverage
• covering
• crust
• eclipse
• envelopment
• eschar
• hiding
• mantling
• masking
• occultation
• pargeting
• plasterwork
• scab
• scale
• screening
• sheathing
• shell
• shielding
• stalactite
• stalagmite
• superposition
• upholstery
• veiling
• wrapping