Like other diamond testing laboratories, the HRD generally
grades their diamonds based on the Four Cs. Each of the
four elements—color, carat, cut, and clarity—is thoroughly evaluated, following
which process the gemologists record their findings on the HRD report.
The council uses a cut scale ranging from Excellent to Poor
when grading their diamonds. To carefully analyze diamonds based on cut, their
gemologists thoroughly investigate the various aspects that constitute a
diamond cut, namely, polish, proportions, and symmetry. Some diamond dealers
often confuse a diamond cut with shape.
A diamond cut refers
to how the shape and polish influence the stone’s symmetry. These are the three
critical elements that HRD gemologists use to determine the overall cut of a
diamond.
The proportions are useful in describing the brilliance of
the diamond. Polish shows the finish of the stone’s different facets, while its
symmetry describes its proportion under certain circumstances and parameters.
Each of these three components is ranked from Fair to Excellent.
After doing away with the cut, HRD experts proceed to the
color. Color grading depends on the extent to which the stone is white or
colorless. The lab generally grades their diamonds using the standard color
scale that ranges from D to Z. A D-graded diamond is the most colorless. In
contrast, a Z-graded diamond has noticeable color hues.
Afterward, the HRD evaluates the diamond’s clarity.
The clarity scale indicates whether the stone has any inclusions. It should be
noted here that these blemishes affect the overall quality of the diamond.
Therefore, the lesser the inclusions, the higher the diamond’s quality.
HRD uses the following
scale to grade their diamonds based on clarity.
- LC (Loupe-clean)
- VVS1 (Very, Very Slightly-Included 1)
- VVS2 (Very, Very Slightly-Included 2)
- VS1 (Very Slightly-Included 1)
- VS2 (Very Slightly-Included 2)
- SI1 (Slightly-Included 1)
- SI2 (Slightly-Included 2)
- P1 (Piqué or Included 1)
- P2 (Piqué or Included 2)
- P3 (Piqué or Included 3)
Carat weight is the last element of the Four Cs that HRD
gemologists investigate and is probably the easiest aspect to hack. Doing so
requires measuring the weight of the diamond using their gemological equipment.
But diamond evaluation does not stop with the Four Cs. The
HRD goes a notch higher by looking into finer details; for example, the experts
examine aspects like girdle size, table width, fluorescence, finish grade, and
culet.
Upon completing the entire grading process, the company
writes a report. The report outlines the quality of the gem based on each
component analyzed. The HRD reports are some of the most comprehensive in the
industry. The company strives to give a brief but precise overview of the
findings, and if there are critical areas that the experts do not test, those
are also noted on the document. The HRD guarantees the accuracy of their
reports by ensuring that each diamond goes through numerous tests.
The company only certifies diamonds that meet certain minimum thresholds for quality control. It distributes those that do not meet the cut to collectors, retailers, or other grading labs for further
testing. However, the HRD ensures that the vendors who buy such diamonds
from the company accurately describe their flaws when selling
them to their clients. That way, a consumer can purchase the gems having all
facts at their disposal.
To avoid any conflicts of interest, graders never know the
owners of the diamonds that they work on.
Besides issuing diamond certificates, HRD provides the following additional services;
- Preliminary
diamond examinations
- Laser
inscription services
- Evaluation and
grading of treated diamonds
- Grading
of lab-grown diamonds
- Evaluation of
repolished diamonds
