Old diamond, brittle or fragile?

[Saphyrose]

Hi!

I have a question regarding my engagement ring which has an OEC diamond.
Ever since I started to work at a shop with a really bright light I have seen that the diamond gets like a halo in the outer rim of the stone.

So my wonder is, is this a sign of brittlement or could it be because of the cutting of the stone?
I have cleaned it and the halo still appears.

Trying to insert a photo of the phenomena.

 

[Karl_K]

cut of the stone
diamond is stable and does not change with age unless damaged..
It is allready millions of years old.

 

[Saphyrose]

Thank you for your answer! Then I don’t have to be nervous that the edges might vaporise