Basalt, Porphyry & Other Monumental or Building Stone

Thickness at import determines classification: slabs greater than 7.5 cm thick fall under 2516900030, while thinner pieces fall under 2516900060, with 2516900000 covering residual cases — a distinction that affects duty treatment and downstream processing declarations. Basalt and porphyry are valued in architectural cladding, countertop fabrication, and civil construction for their density and surface finish. Canada leads US supply, followed by China and Turkey, with Norway and South Africa also contributing meaningful volumes. Importers should confirm whether stone has been merely trimmed or cut to rectangular/square block form, as further processing can shift classification out of this heading.