Each mountain range core and earth vein essence core represents the essence of a mountain or earth vein.
Whether it's a mountain or an earth vein, once someone refines the mountain or earth vein essence core, what awaits the mountain and earth vein is silent collapse.
The mountain naturally crumbles, while the collapse of an earth vein triggers various natural disasters, with earthquakes and ground subsidence being the most common.
Moreover, the essence core of each mountain and earth vein is a part of the origin power of the world they are in.
Though their proportion is very small, if too many are lost, that world would suffer significant harm to its primordial energy.
Thus, almost all world rulers or controllers do not allow anyone to refine and take away mountain and earth vein essence cores.
In the market, mountain and earth vein essence cores are mostly stolen or taken through destructive refining.
This is why mountain and earth vein essence cores are rare.
