Diamond FAQ/Reference thread

Not sure if this is the right place to pose question so moderator move it need be. I am looking to purchase 2 carat cushion, $25k budget. Also traveling to Europe next month, visiting Antwer is not out of the question. Suggestions on purchasing here vs there. What should be reasonable spec Expectations given the budget.
 
There aren't any for fancies. Buy from a vendor that supplies ASET and Idealscope images to gauge proper light return and look for minimal bowtie.
 
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Reposting this since it's come up a lot again:

Cheat sheet which is a great set of numbers for Round Brilliants. There are no set numbers for fancies.

Total depth between 59 – 61.8%
Table diameter between 53 – 57%--ideally 55-57.
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 is more visually appealing.)
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.

Secret sauce is a 55% table, a depth around 59.5-60%, a Crown Angle of 34.5 and a Pavilion Angle of 40.7-40.8.

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. When your table is on the smaller end, the stones are more fiery with more color light return than white light return, when the table is on the higher end, they are whiter (less color light return) and less fiery.

HCA scores: I do not lean on the HCA (Holloway Cut Advisor) as a final decision maker. It's a nice thing to use. Very few stones will get a 4 EX score--the secret sauce will almost certainly get you one that will though. I have seen several serious winners in the 0-2 range, and just as many dogs in the same range just as I have seen some serious winners just outside of it, and many more dogs outside of it. It is a weeder tool to help you look more closely at things.

More input on the girdle: Bruted isn't horrible, my current stone is bruted. Just about everyone will like Faceted better, but bruted isn't a horrible thing. It's not going to ruin your diamond or anything.

I tend to recommend a few specific online vendors more heavily--I vary who I go with depending what I am looking for, and for a reason: most of their stones are AGS graded with a few GIA, their stones are shown with great photography and they do extensive testing that indicates light return and proper cut quality. They also rely heavily on AGS reports, vs GIA, and AGS actually has the authority to call something IDEAL cut. They can prove it. GIA Excellent has a ridiculous margin and many stones that get that grade (or Tiffany's "triple excellent" nonsensical grade) are not actually well cut stones. There's no science behind those grades, where AGS actually has science to prove it is well cut.

Blue Nile is almost never one I recommend because they don't provide either and it's not my ideal to just buy a round on paper. You CAN, but photos and testing really help you identify a winner. I like magnified images, especially those that rotate and zoom to see the inclusions, I like ASETs and I like Idealscopes. Blue Nile does not employ those things.
 
Reposting this since it's come up a lot again:

Cheat sheet which is a great set of numbers for Round Brilliants. There are no set numbers for fancies.

Total depth between 59 – 61.8%
Table diameter between 53 – 57%--ideally 55-57.
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 is more visually appealing.)
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.

Secret sauce is a 55% table, a depth around 59.5-60%, a Crown Angle of 34.5 and a Pavilion Angle of 40.7-40.8.

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. When your table is on the smaller end, the stones are more fiery with more color light return than white light return, when the table is on the higher end, they are whiter (less color light return) and less fiery.

HCA scores: I do not lean on the HCA (Holloway Cut Advisor) as a final decision maker. It's a nice thing to use. Very few stones will get a 4 EX score--the secret sauce will almost certainly get you one that will though. I have seen several serious winners in the 0-2 range, and just as many dogs in the same range just as I have seen some serious winners just outside of it, and many more dogs outside of it. It is a weeder tool to help you look more closely at things.

More input on the girdle: Bruted isn't horrible, my current stone is bruted. Just about everyone will like Faceted better, but bruted isn't a horrible thing. It's not going to ruin your diamond or anything.

I tend to recommend a few specific online vendors more heavily--I vary who I go with depending what I am looking for, and for a reason: most of their stones are AGS graded with a few GIA, their stones are shown with great photography and they do extensive testing that indicates light return and proper cut quality. They also rely heavily on AGS reports, vs GIA, and AGS actually has the authority to call something IDEAL cut. They can prove it. GIA Excellent has a ridiculous margin and many stones that get that grade (or Tiffany's "triple excellent" nonsensical grade) are not actually well cut stones. There's no science behind those grades, where AGS actually has science to prove it is well cut.

Blue Nile is almost never one I recommend because they don't provide either and it's not my ideal to just buy a round on paper. You CAN, but photos and testing really help you identify a winner. I like magnified images, especially those that rotate and zoom to see the inclusions, I like ASETs and I like Idealscopes. Blue Nile does not employ those things.
Hey Ame, what do you mean by bow tie in pear cut diamonds? Also what is a bruted cutlet?

Thank you!
 
Hey Ame, what do you mean by bow tie in pear cut diamonds? Also what is a bruted cutlet?

Thank you!
Bruted GIRDLE. Here is a diagram of the facets of a stone to show you where the girdle is. A bruted girdle is basically unpolished and unfaceted. Some cutters leave a girdle bruted because they think that too much color will reflect back into the stone. It's not a negative, it's a personal preference. Girdles come polished, faceted or bruted.

The CULET is the bottom most facet--usually the pointed tip on the bottom of a round.

For your other question: A bowtie can show up in certain fancies. It's basically when the facets line up in such a way that a "bowtie" shows up in the stone when the light is leaking in those areas (a dark reflection, basically).
 
Hi Ladies. Not sure if this is the right forum for this but need some help to know whether this diamond is good quality or not. Should I keep or upgrade/ buy a new one (at least 1ct).
Appreciate your help. Thanks in advance! ImageUploadedByPurseForum1443897320.673149.jpgImageUploadedByPurseForum1443897331.459430.jpg
 
I took a photo of my ring and earrings after cleaning them this week, thought they may be useful to compare sizes.

From left to right is
3.67crt - 1crt - .51crt

HTH someone!

*forgive the severe color reflection, my formal living room is a deep gold color:Push:

Hi Swanky Mama :smile: Can you post a picture of you wearing your 1carat earrings? :smile: Do you use it for daily wear?
 
Best source to use when buying a diamond engagment ring in your opinion?

That's going to vary by situation. Everyone has different budgetary needs they're meeting, different styles/tastes and certain vendors meet different stock needs/specialties based on the shape/branded cuts of diamond. Basically, people vary so should the vendor spectrum.