canyon to middle light and density masses igneous stone into metamorphic stone
gneiss is metamorphic_rock. igneous_rock is stone. slate is metamorphic_rock. groundmass is igneous_rock. rock is large_rough_stone. amphibolite is metamorphic_rock. metamorphic_rock is rock. metamorphic_rock is stone. marlite is metamorphic_rock. igneous_rock is rock.