新修本草 said it was a glassy substance similar to liúli 琉璃 "colored glaze; glass; glossy gem" that was imported from the Man tribes in the Southwest and from Khotan. In 762, Emperor Daizong of Tang proclaimed a new era name of Baoying 寶應 "Treasure Response" in honor of the discovery of thirteen auspicious treasures in Jiangsu, one of which was glassy langgan beads Coral langgan Tang dynasty herbalists and pharmacists changed the denotation of langgan from the traditional blue-green gemstone to a kind of coral. Chen Cangqi's c. 720 Bencao shiyi 本草拾遺 "Collected Addenda to the Pharmacopoeia" described it a pale red coral, growing like a branched tree on the bottom of the sea, fished by means of nets, and after coming out of the water gradually darkens and turns blue. Langan already had an established connection with coral. Chinese mythology matches two antipodean paradises of Mount Kunlun in the far west and Mount Penglai located on an island in the far eastern Bohai Sea. Both mountains had mythic plants and trees of immortality that attracted Daoist xian transcendents; Kunlun's red langgan trees with blue-green fruits were paralleled by Penglai's shanhu shu 珊瑚樹 "red coral trees". Regarding what variety of blue or green branching coral was identified as this "mineralized subaqueous shrub" langgan. Since it must have been a coral attractive enough to be comparable with the extravagant myths of Kunlun, Schafer suggests considering the blue coral Heliopora coerula. It is the only living species in the family Helioporidae, the only octocoral known to produce a massive skeleton, and was found throughout Pacific and Indian Oceans, although the IUCN currently considers it a vulnerable species. Du Wan's c. 1124 Yunlin shipu mineralogy book has a section (100) on langgan shi 琅玕石 that mentions shanhu "coral". A coral-like stone found in shallow water along the coast of Ningbo Zhejiang. Some specimens are two or three feet high. They must be pulled up by ropes let down from rafts. Though white when first taken from the water, they turn a dull purple after a while. They are patterned everywhere with circles, like ginger branches, and are rather brittle. Though the natives hold … Li Shizhen's 1578 Bencao Gangmu classic pharmacopeia objects to applying the term langgan to these marine invertebrates, which should properly be called shanhu while langgan should only be applied to the stone occurring in the mountains. Li's commentary suggests