Langgan 琅玕 is the ancient Chinese name of a gemstone which remains an enigma in the history of mineralogy; it has been identified, variously, as blue-green malachite, blue coral, white coral, whitish chalcedony, red spinel, and red jade
It is also the name of a mythological langgan tree of immortality found in the western paradise of Kunlun Mountain, and the name of the classic waidan 
In Chinese alchemy, elixir poisoning refers to the toxic effects from elixirs of immortality that contained metals and minerals such as mercury and arsenic
In Chinese alchemy, elixir poisoning refers to the toxic effects from elixirs of immortality that contained metals and minerals such as mercury a
Gu, venom-based poison
Gu (Chinese: 蛊) or jincan (Chinese: 金蠶) was a venom-based poison associated with cultures of south China, particularly Nanyue. The traditional preparation of gu p
Youdu is the capital of Hell in Chinese mythology
Youdu (幽都) in Chinese mythology is the capital of Hell, or Diyu. Among the various other geographic features believed of Diyu, the capital city has been tho
Gate of the Ghosts
The Gate of the Ghosts (simplified: 鬼门关; traditional: 鬼門關), or Devil’s Gate, Demon Gate, known as Guimen guan in 
Diyu (‘earth prison’) is the realm of the dead in Chinese mythology
Diyu (simplified Chinese: 地狱; traditional Chinese: 地獄; pinyin: dìyù; lit. ‘earth prison’) is the realm of the dead or “hell” in Chinese m