Quartzite is a coarse-grained metamorphic rock derived from sandstone.
Heat and pressure combine to fuse grains of quartz sand to make up the composition of quartzite
It has a uniform texture (non-foliated) and is very hard, 7 on the Mo's Scale.
Quartzite is resistant to weathering.
Quartzite is usually white or grey and sometimes pink to red if iron oxides are present as in this example.