Diamonds Education: HRD Cut Grades
HRD, also knows as Diamond High Council (Hoge Raad voor Diamant), is the coordinating body and official representative of the Antwerp diamond sector. It's an official organization, recognized internationally and acting as host, spokesperson and intermediary for the Belgian diamond community. HRD is the Belgian diamond sector's official liaison with governments, and actively promotes support for the diamond sector home and abroad.
The HRD Certificates Department issues quality reports for loose, polished diamonds, describing the personality of your stone based on scientific grounds and according to international standards.
- HRD Cut Grade Parameters
-
Lab
Diamond High Council
(HRD)
Cut >
Very Good
Good
Unusual
Table width %
53 - 66
51 - 67
<51 - >67
Crown Height %
11 - 16
9 - 18
<9 - >18>
Crown Angle %
30.7 - 37.7
27 - 40.6
<27 - >40.6
Pavilion Depth %
41.5 - 45.0
40 - 46.5
<40 - >46.5
Pavilion Angle
39.6 - 42.2
38.5 - 43.1
<38.5 - >43.1
Girdle Thickness %
2 - 4.5
1 - 7.5
<1 - >7.5
Total Depth%
55.5 - 63.9
53.5 - 66.9
<53.5 - >66.9
Culet size %
None - 1.9%
2% - 3.9%
Over 4%
Compared to other grading laboratories, the HRD cut grade parameters appear to be very broad. Allowing diamonds with 66% table percentages in the top cut grade points out how this grading system is of little value in determining the best of the best.
