Complex sentence: Lithic fragments can be any fine-grained or coarse-grained igneous, metamorphic, or sedimentary rock, although the most common lithic fragment found in sedimentary rocks are clasts of volcanic rocks.
Split into simpler sentences: Lithic fragments can be any fine-grained or coarse-grained igneous, metamorphic, or sedimentary rock. Although, the most common lithic fragment found in sedimentary rocks are clasts of volcanic rocks.