Which Rocks term is correctly associated with rock classification: “a clastic sedimentary rock”, and also with “formed by compaction and cementation of sand grains”?

Correct Answer: Option A — Sandstone. Sandstone is correct because it is a clastic sedimentary rock. Sandstone is also associated with formed by compaction and cementation of sand grains. A further identifying fact is that Sandstone is often shows bedding layers. Another useful fact is that Sandstone is associated with commonly used as a building stone. Why the other options are incorrect: Option B — Limestone: It is a sedimentary carbonate rock and is associated with commonly formed from calcium carbonate remains or precipitation; those are the identifying facts of Limestone. Option C — Shale: It is a fine-grained sedimentary rock and is associated with formed from compacted mud and clay; those are the identifying facts of Shale. Option D — Marble: It is a metamorphic rock and is associated with formed mainly by metamorphism of limestone; those are the identifying facts of Marble. Exam Takeaway: Link Sandstone with “a clastic sedimentary rock” and “formed by compaction and cementation of sand grains” for quick revision.