Yes. Agglomerated quartz slabs — the material used for engineered stone countertops — fall under 681099. Antidumping and countervailing duty orders have been imposed on these slabs from certain countries. Importers should confirm the current scope and status of applicable orders with CBP or a licensed customs broker before entry.

Subheading 681011 covers standard masonry units — blocks and bricks used in wall construction. Subheading 681091 covers larger, engineered prefabricated elements such as beams, columns, wall panels, and floor slabs designed to be assembled into a structure. The distinction turns on whether the article is a modular masonry unit or a structural component designed for direct load-bearing assembly.