Quartzites

Quartzites are metamorphic rocks subjected to very high temperatures and pressures; they typically have a light colour and a medium-grain; when they contain mica and quartz, they split naturally and this also makes them ideal for roof tiles and split processing in general (as for slates).
Quartzite is a very resistant material (hardness of 7 on the Mohs scale) and can also be used for external paving, passageways and cladding.
They are often associated with granites, since they share a similar composition (they both have prevalent silicate content) and performance characteristics.
They can also be honed to the same degree of polish as granites.