Krakatau catastrophic eruption in 1883 produced a large amount of pumice in the form of pyroclastic flow or fall. At present, they are on Rakata, Sertung, Panjang, and Sebesi islands. The pumice as the major constituent, often accompanied by obsidian is petrographically and chemically analysed. Most pumice was white with some pink and blackish grey; in various from ash, sand lapilli to block. M…