“My girlfriend wants a one-carat diamond. I’m wondering what tips and tricks you might have for buying the best looking one-carat diamond for around $6-7K. As with most people I imagine, I want the best deal on a 1-carat diamond, but I also want it to be incredible looking. I don’t want to sacrifice light return or sparkle and I want the diamond to be eye clean and be white in color. From what I’ve read, this is going to be something like a VS-2 clarity, F-G color diamond. However, I’ve come to the realization that my expectations are not in line with my budget. Apparently, I’ve got champagne taste on a beer budget as they say. Thus, I’m hoping that you can guide me towards finding a good middle ground. Any help you can provide is greatly appreciated and I will be sure to use your links to buy the diamond so you receive credit for helping me. Thank you.”
The challenge with looking for the best one carat diamond for 6-7K is our perception of what is best. It seems like everybody wants a one-carat diamond engagement ring. By the same token, most people want a diamond that faces-up eye clean and white. That means a minimum clarity of VS-2 and F-G color if you happen to have extremely good vision.
At the same time, everybody wants a diamond that practically sings when they look at it. That means that the cut quality of the diamond has to be superb. The reality is that the majority of standard ideal cut diamonds probably aren’t going to deliver the light performance that you seek. However, sometimes we get lucky, so let’s look around and see what we can find within the scope of my selection criteria.
This 1.00 carat, F-color, VS-2 clarity, GIA Excellent cut round diamond from Blue Nile has a pavilion angle of 40.6 degrees which is offset by a crown angle of 35.0 degrees. This means that the diamond should exhibit a high-volume of light return and a virtual balance of brilliance and dispersion.
The diamond details page provides a high-resolution video of the diamond. However, Blue Nile is not publishing the ASET Scope, Ideal Scope, and Hearts & Arrows scope images provided by the supplier.
The ASET Scope image in the upper right corner looks pretty good. However, there does appear to be slight amounts of light leaking out from under the table facet. That’s what the light pink sections under the table facet indicate.
While people find the presence of light leakage to be alarming, it is important to realize that this is not full-blown light leakage which would look more translucent.
Look closely and you will see that the hearts pattern exhibited by this diamond is not symmetrical. There are significant differences in the size and shape of the hearts. You’ll also see that the tips of the hearts are twisting, which indicates a difference in the length of the lower girdle facets.
If the diamond cutter who produced the one carat diamond from Blue Nile above had spent more time fine-tuning the facet structure, the light performance could have been improved. Just look at how much better the ASET Scope image looks for this 1.018 carat, F-color, VS-2 clarity, Brian Gavin Signature hearts and arrows diamond.
Notice that you don’t see any indications of light leakage under the table facet. At the same time, the pattern of light reflecting throughout the diamond is more uniform and distributed more evenly. This is what happens when a diamond cutter takes the time to align the facets of a diamond more precisely. This is the difference between an ideal and super ideal cut diamond and it’s the kind of thing that you don’t necessarily need a special scope to see.
Take a moment to really see the difference between the Brian Gavin Super Ideal Hearts & Arrows cut diamond on the left and the standard ideal cut diamond on the right. Which of these ideal cut diamonds appears brighter and whiter?
Keep in mind that these are the two diamonds we’re looking at:
Both diamonds have proportions in the middle of the spectrum for the AGS Ideal-0 cut proportions rating. But the Black by Brian Gavin Hearts & Arrows diamond looks brighter because the higher degree of optical precision creates a higher volume of light return. That is why the inverted triangular sections under the table facet appear to be whiter and brighter.
By the way, I want to be sure that we’re both looking at the same thing. I am not referring to the difference in hue and saturation that is visible in these two photographs. I have no doubt that the diamond on the right would look whiter if the photographer took a moment to adjust the camera settings correctly. What I want you to focus on is the difference in brightness that is visible between the arrows under the table facet.
Based on what you’ve told me, if I had 7K to spend on a one-carat diamond, I would buy this 1.022 carat, H-color, VS-2 clarity, Brian Gavin Signature diamond. Seeing that H-color faces up bright and white for most people under normal circumstances, I don’t see a benefit in your spending more for a higher color grade.
In addition, this diamond exhibits medium blue fluorescence which should serve to make the diamond look a little whiter and brighter. Furthermore, if you set an H-color diamond in a platinum or white gold head, it is likely to face-up more like G-color because the color of the white metal is going to reflect throughout the diamond. In other words, you should take factors such as blue fluorescence and the color of the setting when buying a diamond because they are going to affect the appearance.
Now, let’s talk about the cut quality of this diamond. The 40.8 degree pavilion angle is going to produce a high volume of light return, while the 34.3 degree crown angle produces a virtual balance of brilliance and dispersion.
However, you know by now that the proportions of a diamond are only one piece of the puzzle, so you’re going to want to take a look at the ASET and Ideal Scope images for this diamond to ensure that it’s not leaking light.
Spoiler Alert: the ASET and Ideal Scope images for this diamond look outstanding! It’s going to look amazing on her finger!
Todd Gray is a professional diamond buyer with 30+ years of trade experience. He loves to teach people how to buy diamonds that exhibit incredible light performance! In addition to writing for Nice Ice, Todd "ghost writes" blogs and educational content for other diamond sites. When Todd isn't chained to a desk, or consulting for the trade, he enjoys Freediving! (that's like scuba diving, but without air tanks)
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