exposure to extreme heat and pressure changes / metamorphoses sedimentary / igneous rock into metamorphic rock
gneiss is metamorphic_rock. volcanic_rock is igneous_rock. if_rock is very_hot_can_melt. andesite is igneous_rock. combusion_heating_element is heating_element. slate is metamorphic_rock. heating_hydrocarbon is temperature_change. amphibolite is metamorphic_rock. metamorphic_rock is rock. metamorphic_rock is stone.