Diamond Size vs Carat Weight (Yes, There’s a Difference)

Q:

Hi Liz,

Just came across your site today. I have been looking at getting a solitaire engagement ring for my girlfriend. I am looking at getting a .75 – 1.00ct diamond size.

Does this princess diamond look like a decent stone? 1.00ct H VVS1: https://www.jamesallen.com/loose-diamonds/princess-cut/1.00-carat-h-color-vvs1-clarity-sku-258639

I am thinking of pairing it with a simple white gold 4-prong setting.

Thanks for any input you provide.

Rick

Diamond Size vs. Carat Weight

A:

Hello Rick,

Yes, that is a very nice diamond. A simple white gold with 4 prong setting would be a perfect choice.

I did another quick diamond search and came across this virtually identical stone for $4,317.00: https://www.whiteflash.com/loose-diamonds/princess-cut-loose-diamond-2995570.htm (You can read my Whiteflash review on ODBA).

This diamond is still an H VVS1 but the carat weight is .92ct. However, don’t let this deceive you. The measurements of this diamond are  5.36×5.32×3.92, which is a near perfect square with 1:1 ratio, whereas the James Allen diamond measures 5.35×5.27×4.17. Therefore the face-up size is slightly larger and more symmetrical in the Whiteflash diamond. This is because the JA diamond is cut just slightly deeper (4.17m vs 3.92m) which is where you get the excess carat weight. So, the price is more in the James Allen diamond because the carat weight is more, but in terms of what you will visually see, the diamonds will look exactly the same size with the WF diamond being more symmetrical and square.

James Allen (left) 1.00ct H VVS1 princess cut diamond is $4,690.00. It’s measurements are: 5.35×5.27×4.17mm. Whiteflash ACA (right) .92ct H VVS1 is $4,317.00. It’s measurements are: 5.36×5.32×3.92mm. Diamond carat weight doesn’t always equal face-up size.

Even though the James Allen diamond is more in carat weight, the Whiteflash diamond has a better length to width ratio and will face-up slightly larger than the 1.00ct due to a better cut. In this case, it is a smarter purchase to buy the .92ct princess and spend $300 less for a slightly bigger looking diamond. Diamond carat weight doesn’t always equal face-up size.

I hope this helps. Please let me know if you have any questions.

Kind Regards,

Liz

Some Diamond Websites List Cut Grades For GIA Fancy Cut Diamonds? How Is This Possible?

Q:

Hi Liz,

Thanks for getting back to me so quickly. I wanted to let you know how invaluable ODBA has been in my diamond research. I find it concerning that sites will list a GIA report (rated as Ideal) when they don’t score the fancy cut diamonds. How are they able to do this? I am looking at spending around $4,500-5,000. I also would like the diamond size (face-up) of around 5.2 mm x 5.2 mm.

This looks like a pretty good stone: https://www.whiteflash.com/loose-diamonds/princess-cut-loose-diamond-2985948.htm. With those five square green areas that represent less light is that going to have a noticeable impact on the stone’s “pop”?

I love the looks of the diamond you linked to: https://www.whiteflash.com/loose-diamonds/princess-cut-loose-diamond-2995570.htm. Does the difference in the ASET image really warrant a $500 price increase (I can notice the light differences in the standard image)? Also, I will be paying for this with a credit card so the Whiteflash diamond will be around $240 less than the James Allen stone. I can foresee an upgrade in the distant future 5-10 years but I want to make sure what I get now is really going to dazzle her. With the possibility of future upgrades; the Whiteflash certainly looks like the better option.

Lastly, are there any concerns in a thin girdle on a four prong setting? I plan on going with the 14k white gold. Any reason to go with platinum (not really in my budget)?

Again, I really appreciate the straight forward way you present this information. It can be a daunting task going out there alone.

Thanks again for your assistance and clear explanation on diamond size vs carat weight. I will let you know what I decide.

Best,

Rick

A:

Hello Rick,

You are very welcome. Yes, it is concerning which is why I was motivated to create ODBA in the first place. There is so much confusing and misleading information out there regarding the evaluation and purchasing of diamonds. Believe it or not, I truly believe that purchasing online is safer than buying in person simply because the state of the industry requires MORE information and transparency when purchasing on the internet as compared to buying a stone from a traditional jewelry store or diamond district.

First time diamond buyers tend to start at the typical mall jewelry store or local jewelry shop. These are great and they have their place, however if you are looking for a top quality diamond as a lifelong investment then I’d seek elsewhere. If you know where to look online, you will get 10x’s more information regarding a diamonds cut quality (not to mention clarity and color), in-depth light performance information, as well as 30 day money back guarantees. I do believe the rest of the industry will catch up, but it will take some time.

The reason that websites often list a cut grade for a fancy cut diamond is an attempt to help the customer out by defining the cut of the diamond based on what ‘they’ personally consider a good or poorly cut stone to be. Although this may begin with good intentions, it really isn’t accurate.

With regard to your two princess cut diamonds from Whiteflash, both stones show ideal light performance with slightly different patterning. Your .894ct H VVS1 shows a tad more green light reflection but it is still overall a very brilliant stone and a great diamond size (face-up size is near a 1.00ct princess). The actual difference in light performance is slight, so I would go with the lower priced diamond to fit within your budget as that makes the most sense for you. You certainly aren’t compromising on anything. A thin girdle is perfectly fine and recommended for princess cut stones (cause for concern would be extremely thin or knife edge). Platinum is a pure metal whereas white gold is an alloy. Overtime, the white-gold will need to be rhodium plated to retain it’s white appearance. This isn’t a big deal, and if you are planning on upgrading in the future, save the platinum setting for that upgrade. White gold is just as durable. 🙂

I hope I answered all your questions. Whiteflash is an impeccable diamond website and I highly recommend them. As long as you stick with any of their highly prized ACA cut princess diamonds, you will be sure to get a brilliant stone.

Please do let me know what you decide.

I wish you all the best Rick! 🙂

Liz

Q:

Thanks Liz. I’m going with the .894ct H VVS1 since it’s a bit cheaper for me but still a great diamond size!

Thanks again for all your help!

Rick