Wedding Diamond Cut Grading

Proportion of a cut diamondProportion of a cut diamond

Proportion of a cut diamond



Many Diamond experts would consider the cut of a diamond to be the most important of the 4 Cs. A lesser quality diamond well cut would be more sparkling than a better quality diamond poorly cut.
Because diamond cutting is a craftsmanship and is manual in nature, there is no way to ensure the best cut for all the diamonds in the word. Of the 2 major grading certification in the word, GIA and AGS, Only AGS includes the diamond cut into its grading.
There are 2 components to the cut of a diamond, the proportion and direct assessment.
The proportion of the diamond is easily measured by keying the dimensions of the cut diamond into the computer system. There are mathematically calculated “ideal” proportions which would allow the diamond to shine very well.

Direct assessment includes looking at the diamond with a magnifier. The most commonly used is an ideal scope. It is a scope with 10 times magnification where returned light turns out in red, white area represents light leakage. Because direct assessment is done by a human, the same diamond may receive slightly different grading when graded by different people.

Idealscope view of hearts and arrow diamondIdealscope view of hearts and arrow diamond

Idealscope view of hearts and arrow diamond

So what does all these means for us grooms out there looking for a diamond. I’ve compile a few tips for grooms looking at the diamond cut
1) If you are buying a big diamond with a poor cut (which will of course be cheaper), get the GIA certificate and not the AGS one. Then she will never ever know how badly cut it is. And believe me, give her the diamond in spotlight and it will still look pretty sparkling.
2) Of course if you are rich enough, the get a diamond with an ideal cut. Make sure it is AGS certified. There are many smaller labs which certify the cut of a diamond but standards are variable. And if you get an ideal cut, yes then you don’t need the spotlight so much.
3) In Singapore at least, the AGS certified diamonds tends to be more expensive then the GIA certified ones. This makes sense as the jewelers are usually able to tell which are the better cut diamonds and will send them for AGS rather than GIA certification. This is only a general rule though (and one that most girls won’t know J )
4) In AGS certification system, 0= ideal = very good. If cut is important to you, then don’t accept anything more than 1. (Grade 1= near ideal = only experts can tell)
I will provide more tips on buying a diamond in Singapore in future articles. Hope you find this useful for now. 🙂

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