I've learned so much from all your advice here on TPF, so thank you for all the information you've shared with us already! However, I was wondering if you could give a quick breakdown for the best %'s on all the cuts of diamonds (round, square/princess, cushion, marquise, etc.-- I know you've gone through round %'s several times but I think this might be a really helpful reference tool/thread to see these all together and side by side), which cuts offer better light return, most visual size per carat, etc. I apologize if this has already been covered but I'd to hear your knowledge and opinions on each cut. Thanks so much in advance!
Diamond Cut Questions for ame!
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-Light return will be round, always. There are some fancies cut with more defined optics now, but a well cut round will always do it.
-However for color saturation you usually want a pear, cushion or radiant, bec they're cut to retain color vs return light for a round. If you can avoid a round for a fancy those are not really cut for color retention, they're cut for light return.
-Visual size per carat: round OR elongated fancies like pear, marquise and emerald cuts
-As far as numbers: the only cut that has defined numbers for cut quality is Round. Princess kinda does, but not like a Round. Princesses vary a little, they're deeper generally with steeper angles. The rest are a "choose by the ASET and with your eyes" kinda thing.
Cheat sheet which is a great set of numbers for Round Brilliants
And I’d ask the sales person to limit the selection of round brilliant cut diamonds which they offer to me so that all of the diamonds are within the following range of proportions:
Total depth between 59 – 61.8%
Table diameter between 53 – 57%
Crown angle between 34.3 – 34.9 degrees
Pavilion angle between 40.6 – 40.9 degrees
Girdle thickness between thin to medium, faceted (bruted isn't bad, but faceted would be better)
Culet size: none
When you're dealing with a table of 53-54, you want the depth to be in the 59-60 range, not the 61-62 range. I harp on the 55 because it's RIGHT in the middle of the range, and sometimes a 56. The middle of the range is PERFECT, and is always talked about as the perfect table number.
The angles mentioned in degrees are a range, obviously you're going to have interplay, so there's not a specific ratio there. You have to see what the numbers on each stone are. There really is a bigger range of angles than that but ideally those would be great to hit.
Girdle: Bruted isn't horrible, my current stone is bruted. I LIKE Faceted better, but bruted isn't a horrible thing.
-However for color saturation you usually want a pear, cushion or radiant, bec they're cut to retain color vs return light for a round. If you can avoid a round for a fancy those are not really cut for color retention, they're cut for light return.
-Visual size per carat: round OR elongated fancies like pear, marquise and emerald cuts
-As far as numbers: the only cut that has defined numbers for cut quality is Round. Princess kinda does, but not like a Round. Princesses vary a little, they're deeper generally with steeper angles. The rest are a "choose by the ASET and with your eyes" kinda thing.
Cheat sheet which is a great set of numbers for Round Brilliants
And I’d ask the sales person to limit the selection of round brilliant cut diamonds which they offer to me so that all of the diamonds are within the following range of proportions:
Total depth between 59 – 61.8%
Table diameter between 53 – 57%
Crown angle between 34.3 – 34.9 degrees
Pavilion angle between 40.6 – 40.9 degrees
Girdle thickness between thin to medium, faceted (bruted isn't bad, but faceted would be better)
Culet size: none
When you're dealing with a table of 53-54, you want the depth to be in the 59-60 range, not the 61-62 range. I harp on the 55 because it's RIGHT in the middle of the range, and sometimes a 56. The middle of the range is PERFECT, and is always talked about as the perfect table number.
The angles mentioned in degrees are a range, obviously you're going to have interplay, so there's not a specific ratio there. You have to see what the numbers on each stone are. There really is a bigger range of angles than that but ideally those would be great to hit.
Girdle: Bruted isn't horrible, my current stone is bruted. I LIKE Faceted better, but bruted isn't a horrible thing.
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Thank you so much!
So for a princess cut is there a percentage range that is a good guideline (even if not as reliable as a RB)? I just noticed while looking at princess/square modified cuts that they gave percentages for angles like RB; do they do this for all cuts regardless of whether they are reliable/relevant or not?
Sorry for all the questions and thank you again!
So for a princess cut is there a percentage range that is a good guideline (even if not as reliable as a RB)? I just noticed while looking at princess/square modified cuts that they gave percentages for angles like RB; do they do this for all cuts regardless of whether they are reliable/relevant or not?
Sorry for all the questions and thank you again!
For princesses...yes but no. Id say roughly a depth of maybe 74-78%, but the table could be anywhere from say 57/58%-64%. It's again, something you want to see an ASET on. Two companies that do REALLY nice princesses are Crafted by Infinity (skinnier chevrons) and Brian Gavin (slightly wider chevrons). I have seen MANY of the Infinity in person and they are DI-VINE. I think he cuts the tables smaller, I think I've seen most of his in the 58-59 range, but my god they're amazing fireballs.
For the rest: Not really. There's SO much variance, and it's VERY important to select those with your eyes and an ASET. You cannot pick a fancy with just the paper.
For the rest: Not really. There's SO much variance, and it's VERY important to select those with your eyes and an ASET. You cannot pick a fancy with just the paper.
Yeah with all the information you've shared on here I will never buy diamonds site-unseen and/or without the ASETs ever again. Is there a place to find where the most reputable diamond dealers in your area are? For all cuts, if they specialize or not, etc. There are several high end private jewelry stores in my area (lots of old money from the horse breeding and racing industry) but I don't know if they are reliable in terms of quality for the price, etc. Is there like a grading system for stores (I guess kind of like the BBB but only for jewelry stores)?
Look for an American Gem Society jeweler, because they are most likely to have an ASET on site. The reason I suggest that over a jeweler with just a GIA gemologist is because many GIA gemologists do not know what an ASET is, and are not up on technology like, frankly, they need to be to be competitive with the more modern vendors.
http://www.americangemsociety.org/find-a-jeweler
JVC (Jeweler's Vigilance Committee) is supposed to be another one that helps you find a decent one but frankly that has not proven to be very effective in my experience. Many of the ones that I have worked with have been involved with JVC and have been total dirtbags and the times I have needed the JVC to do what is right, it's never done the right thing, in so much that I feel they do more to protect the jeweler than the consumer. The BBB is a lot like that to me as well, they do more for the business than the consumer. But I digress.
http://www.americangemsociety.org/find-a-jeweler
JVC (Jeweler's Vigilance Committee) is supposed to be another one that helps you find a decent one but frankly that has not proven to be very effective in my experience. Many of the ones that I have worked with have been involved with JVC and have been total dirtbags and the times I have needed the JVC to do what is right, it's never done the right thing, in so much that I feel they do more to protect the jeweler than the consumer. The BBB is a lot like that to me as well, they do more for the business than the consumer. But I digress.