Round Cut Diamond

Round Cut Diamond | Diamond Shapes | Diamond Education

Three-quarters of the diamond sold are round cut diamonds! Why? Diamond is all about sparkle and more the sparkle the better. Hence, a major reason behind its immense popularity is its exceptional brilliance. Because of its potential to exude maximum sparkle, the round cut diamond is superior to other fancy shape diamonds and thus, the most preferred choice of all diamond buyers. Round cut diamond also goes by the name brilliant-cut diamond. In fact, practically all round diamonds are brilliant-cut.

 

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History of Round Cut Diamonds:

It was with the publication of the thesis “Diamond Design: A Study of the Reflection and Refraction of Light in Diamond” by Marcel Tolkowsky in 1919, that the brilliance of the round cut diamond gained prominence and recognition. Marcel Tolkowsky was a noted engineer and diamond cutter and in his thesis he compiled a set of precise mathematical computation of proportions and angles aimed to maximize a diamond’s sparkling power. He brought to light the fact that a diamond when cut either too deep or too shallow, would only lose light instead of reflecting them back.

Before Tolkowsky, there were many cutters who were already making use of similar proportions. But it was Tolkowsky who is credited today for introducing a definitive mathematical foundation. Tolkowsky’s original specifications were 59.3 % depth, 53% table, 34.50 crown angle, visible culet. Over time it underwent certain modifications, especially with the advancement in technology.


Modern Round Cut Diamond:

The modern round brilliant cut that we see today is comprised of 58 facets (or 57 with the exclusion of the culet) with 33 on the crown and 25 on the pavilion.


CUT GUIDE

Following is the GIA evaluation of the CUT of a round diamond. The GIA takes into consideration the below mentioned and several other factors while assessing a cut grade.


Excellent Very Good Good Fair Poor
 Table % 53 - 58  52 - 53
or
58 - 60 
51
or
61 - 64
50
or
65 - 69 
< 50
or
> 69
 Depth % 59 - 62.3 58 - 58.9
or
62.4 - 63.5 
57.5 - 57.9
or
63.6 - 64.1
56.5 - 57.4
or
64.2 - 65
< 56.5
or
> 65
 Crown Angle 34 - 34.9 32.1 - 33.9
or
35 - 35.9 
30.1 - 32
or
36 - 37.9
29 - 30
or
38 - 40.5 
< 29
or
> 48 
 Pavilion Depth 42.8 - 43.2  42 - 42.7
or
43.3 - 43.9 
41 - 41.9
or
44 - 45.5 
39 - 40.9
or
45.6 - 48 
< 39
or
> 48 
 Girdle Thin
to
Sl. Thick
Very Thin
to
Sl. Thick 
Very Thin
to
Thick 
Very Thin
to
Very Thick 
Ex. Thin
to
Ex. Thick 
 Culet None Very Small  Small  Medium  > Medium 
 L/W Ratio 1.00-1.01 1.00 - 1.01 1.00 - 1.01  1.02  > 1.02

Color and Clarity

It must be borne in mind that the assessment of color and clarity in round cut diamond varies from person to person. In other word, it is subjective. Each customer will have a unique preference for color and clarity. There are customers who might be absolutely fine with some inclusions in the diamond as long as it is not easily detectable. There are others who have a craze for perfectionism and may opt for the absolutely flawless diamond.

© Copyright 2016 Motek Diamonds by IDC.