Quartzite of the Daspoort formation in the Pretoria Group, in Faerie Glen Nature Reserve, Pretoria. It is nonreactive and resistant to erosion, and consequently forms the crest of the hill. The sandstone layer was transformed to quartzite some 2.1 billion years ago, and was afterwards tilted to the north, towards a very large, ancient magma chamber, situated about 15 km kilometers to the north.