Carat weight and measurements

[Dfordiamond]

Hi,
Do they have something to do with each other?
I found these two diamonds for examples
1.83 7.89*7.95*4.86
1.84 7.89*7.87*4.85
Do they look right?
I’m not making any purchase decision here, just want to get some education thank you everyone.

 

[munchee]

I’m not an expert, with my limited knowledge, what I know is diameter can vary depends on how they cut, it includes many aspects with depth being the most significant (I think), but other aspects also contributes on the diameter.
Sometimes cutter made a deep cut to add on some weight to hit even mark like 1ct, 2ct, 3ct, etc so that it can be priced higher. While sometimes those stone have similar diameter with 0.8s-0.9s or 1.8ish-1.9ish or 2.8ish-2.9ish and so on.
For example my center stone is 2.82ct and the diameter is 9.02mm and my Mom’s diamond is 3.03ct with 9.10mm. With 0.2ct difference the diameter difference is only 0.8mm. While we can find a 2.88ct that have 9.20mm which usually will be listed cheaper than the 3ct.
You can find the exact same carat weight with various combinations of diameter because they have different combinations of depth, table, angles, griddle, etc.
So in buying diamond, we can’t just see the carat weight but also the diameter because there’s a possibility that lower carat weight is actually bigger than higher carat weight.

 

[CutMonkey]

Diamond Carat Weight: Everything You Need To Know

What is a Diamond Carat and how is it measured? Check our diamond carat size chart today to compare diamond carat sizes.

www.pricescope.com

 

[sledge]

Quick check is to calculate the theoretical weight using this formula: length x width x depth x 0.0061

​

Stone 1 = 7.89 x 7.95 x 4.86 x 0.0061 = 1.85956, or 1.86 carats

Stone 2 = 7.89 x 7.87 x 4.85 x 0.0061 = 1.83706, or 1.84 carats

The second stone is nuts on. Some minor "cheating" was done on stone 1.

And not that 0.06mm makes stone 1 "out of round" but it is moreso than stone 2. Again, nothing of concern with either stone, but rather observing a technicality.

 

[Vanilla Bling]

Quick check is to calculate the theoretical weight using this formula: length x width x depth x 0.0061

​

Stone 1 = 7.89 x 7.95 x 4.86 x 0.0061 = 1.85956, or 1.86 carats

Stone 2 = 7.89 x 7.87 x 4.85 x 0.0061 = 1.83706, or 1.84 carats

The second stone is nuts on. Some minor "cheating" was done on stone 1.

And not that 0.06mm makes stone 1 "out of round" but it is moreso than stone 2. Again, nothing of concern with either stone, but rather observing a technicality.

Is this how you would check any stone ? The 0.0061 or is that only for these two stones or do you use that for any stone ? Thank you .

 

[sledge]

Is this how you would check any stone ? The 0.0061 or is that only for these two stones or do you use that for any stone ? Thank you .

The 0.0061 is static and works for any round stone. Again this is theoretical weight and rarely is any stone cut exactly perfect. So expect some reasonable variance. However, if you see much difference it can be a tell-tale something is off.

 

[Garry H (Cut Nut)]

The 0.0061 is static and works for any round stone. Again this is theoretical weight and rarely is any stone cut exactly perfect. So expect some reasonable variance. However, if you see much difference it can be a tell-tale something is off.

For smaller stones use a larger factor as the girdle thickness adds more weight. e.g. 0,00625

 

[Vanilla Bling]

For smaller stones use a larger factor as the girdle thickness adds more weight. e.g. 0,00625

Would this also be for old euros that have thicker girdles as well ?

 

[Garry H (Cut Nut)]

Would this also be for old euros that have thicker girdles as well ?

If the girdle is thicker - yes. If there is a 1mm wide culet add about 0.6mm to the depth etc etc

 

[Vanilla Bling]

If the girdle is thicker - yes. If there is a 1mm wide culet add about 0.6mm to the depth etc etc

Thank you I appreciate your quick reply .