A
rock fragment, in sedimentary geology, is a
sand-sized particle or
sand grain that is made up of multiple grains that are connected on the grain scale. These can include grains which are sand-sized themselves (a
granitic rock fragment), or finer-grained materials (
shale fragments). This definition is used for
QFR ternary diagrams,
provenance analysis, and in the
Folk classification scheme, mainly in sandstones.