Quartzite

Quartzite — the metamorphic rock formed from sandstone under heat and pressure — enters US commerce in two forms under this heading: crude or roughly trimmed (2506200010) and further processed or finished forms (2506200080). Its hardness and chemical resistance make it valuable for dimension stone, countertops, flooring, and refractory applications. Canada and Brazil are the leading suppliers, with Italy, Vietnam, and India also significant sources, reflecting both proximity and the global dimension-stone trade. Classification between the two lines turns on the degree of processing applied before export.