Quartzite

Quartzite

Swan PeakOrdovicianquartzite, just north of Tony Grove Lake,Utah

The quartzite of the Prospect Mountain Formation on top ofWheeler Peak,Nevada

Quartziteis a hardmetamorphic rock.It is formed whensandstoneis squeezed and heated under a chain ofmountains.

Although pure quartzite is white, it usually occurs in shades of pink and red. This happens when it contains someiron oxide(Fe₂O₃). Other colours, such as yellow and orange, are due to othermineralimpurities.

When sandstone is changed to quartzite, the individualquartzgrains and cement materialrecrystallizes.Most of the originaltextureof the sandstone is destroyed by themetamorphism.Minor amounts of cementing materials, iron oxide,silica,carbonateandclay,often move when this is happening. It causes streaks andlensshapes to form in the quartzite.