Limu o Pele
Limu o Pele or Pele's seaweed (Hawaiian, literally "seaweed of Pele" after Pele the Hawaiian fire goddess of volcanoes) is a geological term for thin sheets and subsequently shattered flakes of brownish-green to near-colorless volcanic glass lava spatter, commonly resembling seaweed in appearance, that have been erupted from a volcano. Limu o Pele is formed when water is forced into and trapped inside lava, as when waves wash over the top of the exposed flows of the molten rock.