Andesite: A type of igneous rock that often contributes to the formation of Andisols or volcanic soils.
Pumice: A type of volcanic rock that can be found in some types of volcanic soils. It helps with water retention and aeration.
Lava Flow: The movement of molten rock expelled by a volcano during an eruption. This lava cools down and disintegrates over time to form part of the nutrient-rich volcanic soil.