Metamorphic rocks are formed when another rock is under heat and pressure ... that they are impossible to see without a microscope. Intrusive igneous rocks are formed by magma that has cooled ...

These are formed when either igneous or sedimentary rocks are changed. Heat and/or pressure will cause the elements in the original rock to react and re-form. Metamorphic rocks are highly ...

Petrology is the study of the macroscopic and microscopic mineralogical and chemical composition of rocks. In addition to assessing sedimentary, igneous, and metamorphic rocks that are accessible ...