| Certification
is the key to selecting a quality diamond
at the lowest price. Certification is
your only assurance of quality. A diamond
certification is a detailed diamond quality
report issued by an accredited independent
gemological laboratory. The most recognized
gemological laboratories that provide certified
diamond quality reports to the diamond and
jewelry industry are listed below. Click
on the links to learn details about each
laboratory and report.
Certifications
verses appraisals: It is very important
to understand that appraisals are often
not as accurate as a certified diamond quality
report performed by an independent gemological
laboratory. Appraisals are only as
accurate as the skill, knowledge and training
of the appraiser.
There is
currently no legal educational or training
requirements one must have to appraise diamonds
or jewelry. Appraisals can be done by
anyone, even someone with no training. Appraisals
are often done by the salesperson selling
the diamond. If you read the fine print,
virtually all appraisals include legal disclaimers
to protect the appraiser from legal recourse
if the appraisal is inaccurate. Disclaimers
usually state the appraisal is no guarantee
of quality and is only the opinion of the
appraiser. Many people who buy uncertified
diamonds usually pay to much. What often
appears to be a unbelievable low price usually
turns out to be a diamond that has been
inaccurately graded. It is not uncommon
for a diamond appraisal to be inaccurate
by two, three or more grades when the diamond
is sent to G.I.A. for accurate evaluation.
The quality of the certified diamond
reports can vary somewhat depending on which gemological laboratory
that performs the analysis and certification. It is important
to be understand that grading accuracy is not always consistent
between gemological laboratories. The color and clarity grading
of diamonds are assigned by highly trained Graduate Gemologists
using there individual subjective judgment skills to assign the
proper diamond grades during analysis. Because of individual
judgment some inconsistencies may occur in assigning quality grades.
These inconsistencies are often the result of diamonds which are
on the line between two grades. Fortunately diamonds are rarely
vary more than one grade between gemological laboratories. The primary
geological laboratories that provide certified quality reports are
described below.
G.I.A. - The
Gemological Institute of America:
View
a G.I.A. Diamond Certification
G.I.A. Certified
Diamond Reports provide this information:
- Shape
- Measurements
- Weight
- Depth
Percentage
- Table
Percentage
- Girdle
Thickness
- Culet
Size
- Polish
- Symmetry
- Clarity
Grade
- Color
Grade
- Fluorescence
- Comments
about Diamond
- Plot of
Internal and External Inclusions
A.G.S. - American Gem Society (DQR)
Diamond Quality Report ,and (DQD) Diamond
Quality Document are the best certified
diamond quality report available today.
View
a A.G.S.Diamond Quality Report
Learn
A.G.S. Cut Grade Guidelines.
A.G.S.. Diamond
Quality Reports provides this information:
- Description
- Shape
and Cut
- Weight
- Measurements
- Depth
Percentage
- Pavilion
Depth Percentage
- Table
Percentage
- Crown
Angle
- Crown
Height Percentage
- Pavilion
Angle
- Culet
Size
- Girdle
Thickness
- Polish/Symmetry
- Clarity
Grade
- Color
Grade
- Cut Grade
- Fluorescence
- Comments
about Diamond
- Plot of
Internal and External Inclusions
E.G.L. - The European Gemological Laboratory:
View
a E.G.L. Diamond Certification
E.G.L. Certified
Diamond Reports provide this information:
- Shape
and Cut
- Measurements
- Weight
- Depth
Percentage
- Table
Percentage
- Crown
Angle
- Pavilion
Angle
- Girdle
Thickness
- Culet
Size
- Polish
- Symmetry
- Clarity
Grade
- Color
Grade
- Fluorescence<br
- Comments
about Diamond
- Plot of
Internal and External Inclusions
I.G.I.
- The International Gemological Institute:
View
a I.G.I. Diamond Certification
I.G.I. Certified
Diamond Reports provide this information:
- Description
- Shape
and Cut
- Weight
- Measurements
- Depth
Percentage
- Table
Percentage
- Crown
Angle
- Pavilion
Angle
- Culet
Size
- Girdle
Thickness
- Polish/Symmetry
- Clarity
Grade
- Color
Grade
- Fluorescence
- Comments
about Diamond
- Plot of
Internal and External Inclusions
Three of the
above certification laboratories are the
most reputable , they are the G.I.A, A.G.S
and E.G.L
According
to a study done at pricescope.com http://grading.pricescope.com/
diamond grading is not a science; it is
a subjective skill. Due to the subjectivity
of human color and clarity grading, it is
virtually impossible to say whether one
or another grading lab is absolutely accurate.
Instead all comparisons are made with reference
to the GIA-GTL grades. This decision has
been made because GIA-GTL is the largest
lab and is considered as a market leader.
In half of the cases AGS clarity grading
was one grade stricter than GIA. In two
thirds of cases EGL USA color grading was
one grade softer but clarity grading in
a third of cases was stricter than GIA.
EGL tended to grade clarity more strictly,
An overall fact AGS is very strict. |
