A

David

Darling

quartzite

quartzite

Quartzite. Image credit: Mineral Information Institute.


Quartzite is a hard, massive metamorphic rock resulting from sandstone in which the quartz grains have recrystallized. It is typically colored white, light gray, or yellow, but it also comes in green, blue, purple, and black varieties that contain other minerals. Tough and resistant to weathering it is used in road metal.