Opel has obvious discoloration, but his discoloration is not a long-term phenomenon, it is the reason for the stone.
There are not many gemstones that can change color in a long period of time. It is a feature of high-end gemstones such as Jade, Hotan and Tourmaline.
The discussion about the discoloration of gemstones was caused by a new gem called "Aobao" at a forum.
It is said that this stone change is a long-term phenomenon.