Complex sentence: Mineral physicists study the elastic properties of minerals; their high-pressure phase diagrams, melting points and equations of state at high pressure; and the rheological properties of rocks, or their ability to flow.
Split into simpler sentences: Mineral physicists study the elastic properties of minerals as well as their high-pressure phase diagrams, melting points and equations of state at high pressure. They also study the rheological properties of rocks, or their ability to flow.