Can Holloway Cut Advisor be used on transition cut round brilliant stones?

[stonecurious]

Garry H if you are online, any help with this question would be great. I posted a few days ago that I am looking at two transition cut stones. They have good HCA scores but am unsure if HCA can be used for these types of stones. I also do plan on using one of the appraisers mentioned on the board to evaluate my choice.

original Post is below.

Thanks again

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Hi Everyone,

This is my first post. I''ve been lurking for a while and have learned a ton from the experts here on the board. I think I''ve narrowed it down to 2 stones. Please give me your opinions on these two stones they are both transition cuts with EGL-USA Certs. I also noticed that the EGL website now provides the crown and pavilion angles whereas the actual certs do not. Why is that?


Stone #1
Weight 1.30 CT
Shape TRANSITION ROUND BRILLIANT
Color H
Clarity SI3
Measurements 7.13 x 6.94 x 4.16 mm
Depth 59.3%
Table 59%
Crown 13.8%
Pavilion 41.5%
Crown Angle 33.8°
Pavilion Angle 40.6°
Girdle THIN TO SL. THICK
Polish GOOD
Symmetry GOOD
Fluorescence MEDIUM BLUE
Culet MEDIUM
Cut Grade N/A
Comments

HCA Score = 0.9 Ex/Ex/Ex/Ex

Price: $5200

Note: I noticed that this stone has 3 red/brown crystal inclusions under the table and a large feather on the edge of the table under the microscope. The thing is, it''s eye clean and has great sparkle even when I''ve put it next to other modern ideal cut stones of better color/clarity.




Stone #2
Weight 1.29 CT
Shape TRANSITION ROUND BRILLIANT
Color I
Clarity SI2
Measurements 7.12 x 7.05 x 3.95 mm
Depth 55.8%
Table 57%
Crown 15.1%
Pavilion 37.8%
Crown Angle 34.4°
Pavilion Angle 39.8°
Girdle THIN TO MEDIUM
Polish GOOD
Symmetry FAIR TO GOOD
Fluorescence NONE
Culet VERY LARGE
Cut Grade N/A
Comments

HCA Score = 2.1 Vg/Ex/Ex/Ex

Price: $5400

Note: I have not seen his stone yet but have been told by the jeweler it is eye clean. I will see it this week and post my impression. I''m concerned about the very large culet.


Questions:
Is the price right for both these stones?
Should I go for the H SI3 with the best HCA score or the I SI2 with the larger diameter, higher HCA score and higher price tag?
Is the medium blue fluorescence an issue?
Any thoughts on the crystal inclusions? Do they hurt the value?

Please teach me wise ones.

 

[JulieN]

While the general premise of complementary angles and the inverse relationship between crown and pavilion angles still holds, the HCA is for modern round brilliants.

You might find an ASET scope to be useful.

 

[LGK]

I do believe you actually can use the HCA on antique stones as long as they're truly round and not cushiony shaped like Old Mine Cuts. It's just not as easy to find ones that will fit modern RB standards. And there's plenty that fall wildly outside the modern standards (and thus don't score well on the HCA) that are still pretty. I have an OEC that scores 1-something on the HCA. Personally I tend to use the HCA on them as kind of an afterthought- shopping for antique stones is more like buying a fancy shape, in that you need to see them to really judge, and an ASET scope doesn't sure hurt either.

Since you've seen the 1st one and like the way it performs, and it's eye clean enough for you, that would be my choice. Of course it can't hurt to compare it to the second one when you can, but the really shallow depth on the second one kinda turns me off. I'd probably have whatever you decide on appraised; they're EGL certs I presume? Most antique stones are, if any cert at all. That way you'd have a better idea if the price is right. Without knowing how accurately EGL graded them it's tough to guage if the price is right. It can be difficult to find whiter antique stones.

Medium fluoro shouldn't be a problem. Overblues (the milky/oily look in the sun) are really rare, and they're only a tiny proportion of the strongly or very stronly fluorescent stones. Medium should be fine, and might boost the color a smidge.

As far as value goes, and regarding the inclusions- get an independant appraisal. I'd ask about the feather near the girdle on the first one too, if it is a durability issue. Since it's survived this long, I'd guess not- but if it's a GIA equivalent I1, and it's the grade making inclusion, I'd ask a professional to be sure.

Good luck! Definitely post pics when you can