I'm loving an HCA 2.1? (This was unexpected!)

[GemView]

Hello all,

I made my fourth lab diamond purchase recently.

My first consisted of a 3/4 carat pendant in yellow gold three years ago. That stone knocked my socks off and sold me on lab diamonds. (Not IGI certified but sold as F, VVS. Incredible scintillation and a very crisp arrow pattern is visible using an ideal scope.) To complete the set, I added a pair of 1CTW lab diamond stud earrings (CVD type). Then, a year or so ago, I bought an IGI Ideal 1.05 carat from Dreamstone, E, VS1, (CVD) with an HCA of 1.3. It was set into a 14K white gold pendant to match my e-ring (stone faces up bigger than average and has the edge on brilliance but not quite the level of fire/scintillation as the uncertified stone).

In contrast to the above, my original earth-mined diamond from my engagement ring is a 1.04 carat, F, SI1, "Ideal Plus" (EGL USA) with an HCA of 1.7 set in 18K white gold. In that case, I already owned the stone for a number of years before I viewed it through an Ideal Scope and was surprised upon doing so that I can't see the clear arrow pattern I expected, yet it shows under the right lighting, as also captured in my original profile pic.

Most recently, I bought a classic Tiffany style ring, 1.35 carat, D, VS1, in 14K yellow gold.

Due to the price/retailer (JTV), this ring was not sold with the ability to see the IGI "Ideal" specs beforehand but upon receipt I was pleasantly surprised to see the IGI cert also says it is an HPHT. My first impression out of the box was "Wow!" The fire and brilliance is a great balance under just about any lighting. (Pics attached. Please ignore my super dry skin!)

Well, imagine my reaction when I plug the numbers into the HCA and it's a 2.1!

I should probably mention that I was skeptical of how good an LGD I could buy in a setting for the price, so I ordered two (the other one isn't here yet). However, while plugging the cert number into the HCA, I noticed that when I checked the "H&A" this 1.35CT swaps from a 2.1 to a 1.9 HCA score. And so with that introduction, my questions:

Since the stone is already mounted, is it enough to use a generic Ideal Scope to view the arrows through the top of the stone? In other words, is it safe to assume that if the diamond was dismounted it would also exhibit the hearts if viewed from beneath?

Second, I am trying to figure out why this stone seems cut to impress despite the fact that it is the lowest-ranked HCA of the lab diamond purchases I have made? (For example, would this be considered a Tolkowsky ideal cut? Or an AGS 0?)

This is not to say there aren't better to be had out there. (Plenty of eye candy on PS attests to that!) However, one of my concerns when I first jumped on the LGD bandwagon is that their near-perfection might make my (sentimental) earth-mined diamonds look vastly inferior.

In this case, I can't say my earth-mined e-ring diamond is inferior — but despite the better HCA it's not a notably better, either. Might this be because my earth-mined stone is F/SI1 whereas this is a D/VS1? (Or maybe I just need a professional cleaning?)

Here are the HCA 2.1 lab stone stats. What to make of this?

Carat:	1.35
Depth:	62.3
Table:	56
Crown:	34.9

Pavilion:	41
Symmetry:	Excellent
Measurements:	7.09x7.06x4.40
Crown %./Pavillion %:	15.5% / 43.5%

 

[Karl_K]

With different minor facets and optical symmetry that combo can range from awesome to slight under table leakage but still very very nice as long as there is no wonky cutting going on.
So there is no surprise that you like it.

The HCA is basically saying its on a line.
The HCA can not tell where it is near that line that takes an Ideal-Scope or ASET image to be 100% certain.
Pictures look good, its not wonky.
If you love it and viewed it in your environment in different lighting conditions. I would not worry about the HCA score.

 

[Garry H (Cut Nut)]

With different minor facets and optical symmetry that combo can range from awesome to slight under table leakage but still very very nice as long as there is no wonky cutting going on.
So there is no surprise that you like it.

The HCA is basically saying its on a line.
The HCA can not tell where it is near that line that takes an Ideal-Scope or ASET image to be 100% certain.
Pictures look good, its not wonky.
If you love it and viewed it in your environment in different lighting conditions. I would not worry about the HCA score.

if you click the H&A's for optical symmetry up to 2.5 HCA can pass!

 

[Karl_K]

You can certainly use an Ideal-scope on a mounted stone its just harder to do and take pictures but for viewing yourself its easy.
To take pictures you need to hold the ring, camera and scope then try and get the light right while everything is perfectly aligned so its not a lot of fun.

 

[GemView]

You can certainly use an Ideal-scope on a mounted stone its just harder to do and take pictures but for viewing yourself its easy.
To take pictures you need to hold the ring, camera and scope then try and get the light right while everything is perfectly aligned so its not a lot of fun.

It's worth a try. I'll see what I can post after I rig up some sort of setup to photograph. Thank you.