Which of the following is NOT a type of metamorphic rock?

Granite is not a type of metamorphic rock; it is an igneous rock. Igneous rocks form from the cooling and solidification of magma or lava. In contrast, metamorphic rocks, such as slate, schist, and gneiss, originate from existing rocks—either igneous, sedimentary, or other metamorphic rocks—that undergo transformation due to heat, pressure, and chemically active fluids.

Slate forms from shale, schist evolves from slate or other fine-grained rocks, and gneiss typically originates from granite or another type of rock through intense heat and pressure. This process of metamorphism results in changes in mineral composition and structure, distinguishing metamorphic rocks from igneous ones like granite. Recognizing the fundamental differences in rock types based on their formation processes helps in understanding geology and the rock cycle.