a sedimentary rock consisting of sand consolidated with some cement (clay or quartz etc.)
"The geologist examined the exposed layers of sandstone to confirm that its grains were indeed bound together by silica cement."
A sedimentary rock produced by the consolidation and compaction of sand, cemented with clay etc.
"The ancient cliff face crumbled as rainwater seeped into the porous layers of sandstone formed from compacted grains cemented together by clay."