Post # 1
Ok so my diamond is a little under a 1/2 ct and I got an awesome deal on my ering so this doesn’t really bother me but it is Gia graded excellent cut so I plugged the stats in the hca tool and it says I have a “good” diamond With a score of 4 but I’m confused bc GIA graded it as an excellent cut?! So it only visually looks like a very good cut diamond?
I love that I can come on here and ask questions about this stuff, that I have no idea about, and always get such awesome answers and insight so thank you guys! 🙂
Edit: here are the measurements
Post # 3
@MissSweetiepie: Not all GIA Excellent cut grade diamonds are created equal. In fact compared with the AGS ideal cut grade, GIA’s grade is quite broad. The HCA is meant to be a rejection tool to weed out the lower performing ones. It also has its own ‘preferred specs’, so a high HCA score doesn’t make it a bad stone for a fact, rather it predicts that there are better ones out there.
There are many combos of angles that make a great performing stone, each with their own characteristics (more fire or brilliance for example).
That being said, your stone’s pavilion angle is steep when combined with the crown angle. Generally speaking, a good combination for a 35 crown would be 40.6-40.8 pavilion. A 41 pavilion would complement a 34.0-34.5 crown well. A 59 table is considered to be on the larger side
It’s difficult to make an assertive comment since GIA rounds the numbers (for example, a 41.15 pavilion becomes a 41.2, which is actually significant). I doubt it would have made the AGS ideal cut grade, but then again I’m not an AGS grader and I don’t have the stone.
To be clear, I don’t mean to put down your diamond in any way! The HCA is primarily used for people who are trying to narrow down diamond choices. A score below a 2 actually means that it’s worth investigating the stone further (with an idealscope/ASET). It’s by no means a perfect tool. You have your diamond already, so unless you’re seriously considering returning it for another, just enjoy it!
I recommend making a thread on Pricescope, I have nowhere near the amount of experience experts there do. Garry Holloway posts on occassion too, so you can ask the HCA creator himself.