Which Rocks term is correctly associated with rock classification: “a low-grade metamorphic rock”, and also with “formed mainly from shale under pressure and heat”?

Correct Answer: Option A — Slate. Slate is correct because it is a low-grade metamorphic rock. Slate is also associated with formed mainly from shale under pressure and heat. A further identifying fact is that Slate is splits into smooth thin sheets. Another useful fact is that Slate is associated with used for roofing and writing boards. Why the other options are incorrect: Option B — Quartzite: It is a hard metamorphic rock and is associated with formed from sandstone rich in quartz; those are the identifying facts of Quartzite. Option C — Granite: It is an intrusive igneous rock and is associated with formed by slow cooling of magma below the surface; those are the identifying facts of Granite. Option D — Basalt: It is an extrusive igneous rock and is associated with formed by rapid cooling of lava at the surface; those are the identifying facts of Basalt. Exam Takeaway: Link Slate with “a low-grade metamorphic rock” and “formed mainly from shale under pressure and heat” for quick revision.