Must be Tiffany ! U cannot compare it with other ring as most of them just the replications of the signature Tiffany design (emoji)(emoji)(emoji)
Tiffany only picks the best quality from the diamond pool, and the means under the same grading, Tiffany’s diamond will be whiter than average.
Also, Tiffany doesn’t provide GIA certificate (一份沒有法律效應的report). Tiffany’s diamond has a legal terms claiming that if ur purchased diamond is at a lower grade from any report, a refund or return can be made. It implies there diamond will have at least the same quality of the GIA (or even better).