Aragonite-bearing basalt means that the pores of vesicular basalt are filled with secondary minerals such as calcium carbonatecarbonate, chalcedony,limonite.Aragonitein Penghu is famous for its concentric circle pattern, which is quite rareunique. Wangan Islet in South Sea is a famous place of origin for aragonites. The specimens collected by this center are from Tiantai Hill of Wangan Islet.