Increasing metamorphic grade leads to larger crystal/grain sizes due to recrystallization process in response to higher temperatures.
In general, as you increase the metamorphic grade of a rock, the crystal/grain size increases. This is due to the recrystallization process that occurs in response to increased temperatures during metamorphism. Larger grains are more stable than smaller grains because they have a lower surface area to volume ratio.
Annealing in metallurgy, where smaller mineral sizes fuse into larger crystals, is akin to recrystallization in metamorphic rocks. The metamorphic grade progression slate → phyllite → schist → gneiss illustrates increasing metamorphic grade levels.
A figure depicting the recrystallization process in a sedimentary rock transforming into a metamorphic rock with larger, interlocking quartz crystals due to increased temperature conditions visually represents this phenomenon.
https://brainly.com/question/8059002