Diamond has no fire

[Karl_K]

Given that this stone seems to have extremely good clarity under 40x magnification, and given what you've described, it sounds like GIA will have graded down the clarity due to a slight milkiness.

Hi welcome to PS!
While I agree that a GIA graded stone even up into the vs range can sometimes have some milkyness in this case a feather from the girdle to almost touching a star facet is a SI grade setting feature and the cause of the grade.
I am not seeing any signs of issues in the image.

My guess is that it is eyesite and expectations of more fire related than anything.

 

[Garry H (Cut Nut)]

Given that this stone seems to have extremely good clarity under 40x magnification, and given what you've described, it sounds like GIA will have graded down the clarity due to a slight milkiness. This level of milkiness would only be visible when side by side with a full fire stone, which is why you didn't notice it beforehand. You can have no inclusions, perfect proportions and an SI grading from GIA and still get milky stones, depending on how severe it is. Obviously GIA will grade lower I1-I3 as the milkiness becomes more obvious.

Very likely the case. GIA rarely note internal graining which is often present when I view professional videos of diamonds.
This is rarely visible in 360 consumer videos.

 

[Daisys and Diamonds]

@Garry H (Cut Nut) you are such a wealth of information
im off to find a broadleaf tree forthwith