Classification Information
Building materials, not of metal; rigid pipes, not of metal; asphalt, pitch and bitumen; buildings, transportable, not of metal; monuments, not of metal; marble, silica (quartz), glass, xylolith, gypsum, stone, slate, granite, sandstone, concrete, brick, ballast, limestone, lime, rock crystal, quartz, asbestos, clay, ceramics, alabaster
Nonmetallic Building Materials