Foraminifera beach rock is formed by sedimentary cementation of foraminifera shells, coral detritus, seashell fragmentsbasalt gravel,is one of the very special sedimentary rocks in Penghu. This kind of beach rock has been immersed in seawaterexposed to sunlight for years. Affected by differential erosion, the rock mass usually has largesmall potholes, looking like coral reef limestone. This kind of beach rocks can be easily seen at the northern seaside of Zhuwan Village, Hejiethe seaside of Hsiaomen. The specimen you see was collected from Guoye Village of Huxi Township.