sent is a mean of sedimentary stone
sedimentary is rock. sedimentary_clay is soil. papyrus_sheet is writing_surface. limestone is sedimentary_rock. sandstone is clastic_sedimentary_rock. clastic_sedimentary_rock is sedimentary_rock. papyrus_scroll is tangible_thing. slate is sedimentary_rock. sedimentary_rock is rock. sedimentary_rock is stone.