This object is a specimen of Pumice Stone (Batu Apung), a unique volcanic rock that forms part of Indonesia’s geological heritage. The stone is irregularly shaped and quite substantial in size. Its physical characteristics are very distinct: the surface is extremely rough and has the texture of dried foam, covered with countless tiny pores and cavities. Its dominant colors range from pale light brown, cream, to whitish-grey. This highly porous texture is the result of the magma cooling rapidly, trapping gases within before the rock fully solidified, which is why it is exceptionally lightweight. This particular pumice stone specifically originates from the Padang Pariaman region of West Sumatra. This provenance places the specimen within the context of the active volcanic mountain range along the island of Sumatra, emphasizing its geological value as a typical product of local volcanic eruptions.