The Láng tree or the Láng gem
(Not a Langgan but a tea tree. Langgan is invisible in photos)
Verse 79 Shadows on white jade
Affairs settled but in their core not yet
People satisfied but in their core not yet
You want to know what really to believe
The sun casts shadows on the Láng
The sun casts shadows on the Láng tree
The sun casts shadows on white jade
琅 Láng means '(beautiful) sound', but since shadows cannot fall on a sound, it has a different meaning in this poem.
琅玕 Lángán is an ancient name of several gemstones, often white ones. Especially a 'lithophone', a stone which makes a sound when struck.
Ancient Stone Chimes. Shandong Provincial Museum, Jinan
Lithophone: a Chinese stone chime consisting of 16 stone slabs
hung in two rows and struck with a hammer.
Lángán is also the name of a mythological tree of immortality, found in the western paradise of Kunlun Mountain.
琅玡 Lángyá is the name of a mountain in Shandong Province, China.
And finally 琅玕
Lánggán is the name of the classic alchemical elixir of immortality 'Lánggán huádan'.
The meaning which fits in the oracle text are the tree and the stone. Shadows can appear on a tree or a stone when the sun goes down. Information from Wikipedia
Sunset is a metaphor for growing older. The time when mortality invades the mind. Many stories and myths deal with this uncomfortable thought.
When this time comes closer, the need to know the core of everything - of life itself - also comes closer.
The character Láng combines 'jade' with 'good'. The character Gán is 'jade' with 'trunk'. The Lánggán: the Láng tree.
Láng is actually 'jade-like stone', it does not really specify which stone it is, but the lithophone quality makes it special.