Losing ct. weight in depth?

[me1234]

Regarding round diamonds, is there a point that one that is cut too deep, you''re actually paying for something that looks less than its stated weight? I am looking at 2 ct. rounds and don''t want to pay for something that has ct weight that can''t be seen. What dimensions should I stay away from?

 

[Mara]

Well a 2c round should have a diameter of around 8.2mm. That does not mean that if the diameter is slightly larger or smaller that the stone is automatically a dud. You need to look at other #'s as well and the stone's specs. But if you want to use a loose #..use 8.2mm or around there.

A short tutorial on diameter...don't know how much you know about it.

If a 2c well cut round should be around 8.2mm...then if you buy a 2c round that has a diameter of 8.05mm you are probably losing some of the ctw in the depth or pavilion area or maybe to an overly thick girdle. For whatever reason, wherever that extra carat weight is hiding, it's NOT in the diameter which is what is visible face up to the eye. Unless you are getting a spectacular price then I would not pay for a 2c stone that doesn't look like one. Your stone may have a smaller table and possibly more fire than white brilliance. It's a preference thing.

On that same token, if you buy a 2c round that has a diameter of around 8.35mm, then your depth is probably slightly shallow, putting more of that ctw up top in the diameter where it's visible. Out of the two scenarios, this one works better for me (I have a stone like this) if you decide not to go with an 'ideal' (or around 8.2mm) because you see more of the diamond and it looks bigger than the 2c round..maybe more around 2.10c or similar. But the difference is visible. Just as in the last scenario, the different is visible, it will look smaller than 2c. Slightly shallower stones tend to most likely carry larger tables, and shallower depths. Be careful with this as you may lose some of the fire associated with the stone and gain more white brilliance. If you like that way that looks, great..some may not. Also be careful you do not fall into fish-eye territory while looking at these types of stones. That's definitely not attractive.

Of course the last scenario is that you get something around 8.2mm average, well cut etc and then you don't have to worry about it looking bigger or smaller, it will look like what it is, the crown and pav angles will be nice and all will be well

Or should be anyway.

Oh and lastly...I am sure you already know this but diamonds have diameter ranges, it will be hard to find a stone that is 8.2mm all the way around..as most diamonds are not that perfectly round. It will be more likely to have a stone that is something like 8.16-8.20mm in diameter, or similar. The smaller ranges are better, stay away from any ranges with huge fluctuating amounts, like 7.90-8.30mm or something ridiculous. That stone will be out of round and will not look round to the eye at that point most likely.

Good luck!

 

[me1234]

Thanks Mara, that was a big help! So would a diamond that has a range of 8.2-8.22 theoretically look slightly larger than a 2ct? Thanks again for the help : )

 

[Mara]

A stone that is 8.20-8.22mm in diameter will look pretty much spot on like a 2c should. For you to start seeing any visible differences in diameter changes...(though it depends on your eyes...) I would roughly estimate you'd need to see something like a 8.30-8.34mm or similar stone for there to be a visible difference from a 2c. Same the other way as well.

The interesting thing to note is that because so many people buy their stones are a maul jeweler or similar or have no idea what they bought...they tend to just use ctw as a gauge. So someone may tell you, this is a 2c stone and you think...wow it looks huge! But maybe it's a larger spread stone. On the same token, someone may tell you this is a 2c stone and you think, hmm it's smaller than I thought. Chances are it's a little deep and looks smaller than it should. But people don't always care about that...it's a 2c that is all that matters!

So keep that in mind as you walk around viewing the average jane's rings...gauging a co-worker on her ring size and that type of thing may not be accurate, it all depends on the cut, which most people don't know.

 

[aljdewey]

----------------
On 8/13/2003 12:24:49 PM Mara wrote:

The interesting thing to note is that because so many people buy their stones are a maul jeweler or similar or have no idea what they bought...they tend to just use ctw as a gauge. So someone may tell you, this is a 2c stone and you think...wow it looks huge! But maybe it's a larger spread stone. On the same token, someone may tell you this is a 2c stone and you think, hmm it's smaller than I thought. Chances are it's a little deep and looks smaller than it should. But people don't always care about that...it's a 2c that is all that matters!

----------------

Mara brings up an excellent point, me1234, and that is this: carat is a weight measurement, not a dimensions (size) measurement.

In the "maul"/mall setting, keep in mind that they typically don't carry stones cut to excellent proportions. Cutters (and subsequently retailers) are motivated to get as much money from a stone as they can, so if cutting it a little thicker in the girdle or a little deeper in the pavilion allows them to reach the magic 2ct mark (or 1 ct., or 1.5....all are points at which the price-per-carat goes up), they can get more money.

So Mara's right......you could have 3 people all show you their 2-carat stones, and it's entirely possible they all look sized differently. As she pointed out, the key is to find a stone that carries all of its carat weight properly so you can "see" what you're paying for.

 

[fire&ice]

Another thing to consider - outside the measurements - is your setting. Higher prongs tend to make the stone "appear" larger while lower set stone have a lower profile.

Also, a sl. thick girdle is not necessarily a bad thing. It will *indeed* effect the measurements; but, can be extra protective, especially in a 4 prong setting. Personally, and ideally, I would buy a med/to sl. thick girdle in a stone this size....just for my piece of mind...but then I would not consider to set in a 6 prong.

That said, as others noted, it is very important to focus on the mm's of a stone. It can tell you quite a bit. As a general rule, over 62.99% depth is considered out of cut class 1. Many other factors determine cut grade, but that's the depth %.

Also, a well cut stone will appear larger than a dud.