Marble, slate, and quartzite are much harder rocks than limestone, shale, and sandstone.
Metamorphic rocks are rare in Kansas.
Quartzite, which is found in a small area in Woodson County, is the only native metamorphic rock found at the surface. Quartzite boulders can be found throughout northeastern Kansas, but they were not formed there. Glaciers carried the rocks in from South Dakota, Iowa, and Minnesota. They are red, brownish red, or purple. Igneous Rocks Igneous rocks are formed when a hot liquid, called magma, cools and changes from a liquid state to a solid state.