Diamond is stable at extreme pressures. To the top Conclusion Metamorphic rocks form from heat and pressure. Some of the minerals that make up those rocks also change properties as heat and pressure is applied. Polymorphs of minerals at different phases result and thus some minerals are only found in metamorphic rocks.ome of the minerals that make up those rocks also change properties as heat and pressure is applied. Polymorphs of minerals at different phases result and thus some minerals are only found in metamorphic rocks.