Final answer:
Metamorphic rocks are rocks that have been transformed by heat and/or pressure. They can vary in grain size, fizz in HCl acid, and typically contain calcite or dolomite minerals.
Step-by-step explanation:
The subject of this question is Metamorphic Rocks, which are rocks that have been transformed by intense heat, pressure, or both. These rocks may have different grades depending on the degree of metamorphism they have undergone.
Metamorphic rocks can exhibit various characteristics, such as a range of grain sizes from fine to coarse, fizzle in HCl acid, and commonly have coarse crystalline textures. The primary minerals found in metamorphic rocks are usually calcite or dolomite.
Examples of metamorphic rocks include quartzite, gneiss, and schist. Each of these rocks has distinct properties and can be identified based on their composition and geological context.