Looking at the chart, what do the numbers and letter for a cut represent for example A1. Also, I noticed that on the chart for the same cut range, and carat range that a E color SI1 is less expensive than a F color SI1. Why would that be? Thanks.
From what I have learned on here (trying not to offend anyone), if the diamond has an AGS certificate, it has a slightly higher price than a diamond with a GIA certificate. An AGS Ideal also has stricter standards than an GIA Excellent. So...IF the E diamond is a GIA Excellent, and the F is an AGS Ideal, the AGS may cost more. Plug in the numbers of both stones into the Holloway Cut Advisor (HCA) to make sure they BOTH fall under 2.0. You may find that some GIA Excellent stones do not get under 2.0 (ie are bad performers). In general tho, if a stone has a better cut (ie better performer), you will be paying more.