Shale:
* Low-grade metamorphism: Shale turns into slate, a fine-grained, often dark-colored metamorphic rock with a distinct cleavage.
* Medium-grade metamorphism: Slate further transforms into phyllite, a rock with a slightly coarser texture and a sheen.
* High-grade metamorphism: Phyllite can then transform into schist, a metamorphic rock with a more pronounced foliation (layered structure) and larger mineral grains. Depending on the minerals present, schist can have a wide variety of colors and textures. At even higher temperatures, schist might change into gneiss, a banded metamorphic rock with alternating layers of light and dark minerals.
Granite:
* Metamorphism: Granite is already a relatively hard and resistant rock. When subjected to heat and pressure, it transforms into gneiss. The original mineral composition of the granite will influence the appearance of the gneiss.
Important Note:
* The specific metamorphic rock formed depends on the degree of heat and pressure, the original composition of the rock, and the presence of fluids during metamorphism.
* There are many other metamorphic rocks that can be formed from shale and granite, but these are some of the most common.
