Luobi Cave Luobi Cave Luobi Cave () is a karst cave under the west face of Yin Ridge (印岭) located north east of Lizhigou Town (荔枝沟镇), from Sanya City, Hainan Province, People's Republic of China. The entrance to the cave is approximately high and wide. Inside the apex reaches a height of with a floor area of about Two large stalactites hang down from the roof like large pens, hence the cave's name. A number of inscriptions carved into the walls of the cave are believed to date to the Yuan Dynasty (1271–1368). One of these refers to the precise date of
Calcium carbonate caves. Two hydrated phases of calcium carbonate, monohydrocalcite, CaCO·HO and ikaite, CaCO·6HO, may precipitate from water at ambient conditions and persist as metastable phases. In contrast to the open equilibrium scenario above, many swimming pools are managed by addition of sodium bicarbonate (NaHCO) to about 2 mM as a buffer, then control of pH through use of HCl, NaHSO, NaCO, NaOH or chlorine formulations that are acidic or basic. In this situation, dissolved inorganic carbon (total inorganic carbon) is far from equilibrium with atmospheric CO. Progress towards equilibrium through outgassing of CO is slowed by (i) the slow reaction HCO