You need to test the actual slabs you are considering. Look for the Geology threads by karin_mt where she lists several easy tests to determine hardness and porosity.

Sometimes slab yards make up their own names for stones ... buyer beware!

Generally many of the "white" quartzites are really marble or dolomite.

Some slabs might be hard like quartzite, but porous like a 'sponge', which doesn't work well for kitchen counters.

You need to test the actual slabs.

There are over twenty quartzite horror threads here on Houzz. Much of it is unsuitable for use as countertops. Picking a fabricator who stands behind what he sells is even more important than the material you select.