The Wayback Machine - https://web.archive.org/all/20050216100409/http://www.ajediam.com:80/Diamond_appraisals_grading_ratings_course.html
How to buy diamonds, understand a diamond report:
The first criterion: Size of the diamond. You can see it.
Your Diamond is big or small ! (Weight + size are expressed in Carat
The Second: Color: You can see it.
Your Diamond is White. (D, E, F, G, H, I are White Color indications)
The Third: Brightness: (Cut) You can see it.
Your Diamond has the best Brightness or not.
Brightness is obtained by the art of Cutting and Polishing
On the Diamond Certificate you must find following grading:
(Proportion: very good to good / Finishing & Symmetry: Very Good to good)
The Fourth: Clarity: That's what you see by naked eye (Eye Clean)
and by loupe (Loupe Clean).
If you can't see any inclusion it's the best Clarity. (VS1 to SI 3 and some I1+)
Everything situated above is not important because you can't see it.
Better Clarity is invisible, is much more expensive and you can see the difference only by microscope.
The Fifth: Fluorescence: or Photoluminescence
When diamonds are strong Fluorescent it can quote the color to a lower quality in facts of lower Color and Clarity.
Your diamond has the best quote: NIL (no fluorescence)
If the diamond is of a lower Color, slightly tinted White, the fluorescence can enhance the Color to White. (maximum medium fluorescence)
Than it is a positive fact.
Learn about diamonds, the four C's
Carat, Color, Cut, Clarity and fluorescence:
We describe the four C's for diamonds.
4 C's of diamonds: Carat, Color, Clarity, Cut / Shape
Carat :The weight of diamonds is expressed in Carats. One Carat has a weight of 0,20 gram.
Sizes of Diamonds - The diameter of a diamond depends of the shape of the diamond.
Here we give you indicative sizes for round brilliant diamonds - sizes on the girdle:
The size of one Carat Diamond is about 6.5 mm
The size of 0.25 Carat Diamond is about 4.1 mm
The size of 0.50 Carat Diamond is about 5.2 mm
The size of 0.75 Carat Diamond is about 5.9 mm
The size of 1.00 Carat Diamond is about 6.5 mm
The size of 1.50 Carat Diamond is about 7.4 mm
The size of 2.00 Carat Diamond is about 8.2 mm
The size of 2.50 Carat Diamond is about 9.0 mm
The size of 3.00 Carat Diamond is about 9.3 mm
The size of 4.00 Carat Diamond is about 1.02 Cm
The size of 5.00 Carat Diamond is about 1.10 Cm
The size of 6.00 Carat Diamond is about 1.17 Cm
The size of 7.00 Carat Diamond is about 1.24 Cm
The size of 8.00 Carat Diamond is about 1.30 Cm
The size of 10.00 Carat Diamond is about 1.40 Cm
The size of 15.00 Carat Diamond is about 1.63 Cm
The size of 20.00 Carat Diamond is about 1.76 Cm
Color : The Color of diamonds. Diamonds exist in all colors of the rainbow. The diamond grading laboratories have standardized the color grading.
The most desired are colorless diamonds:
Rare White + D,
Rare White E,
Exceptional White + F,
Exceptional White G,
White H, I
Slightly tinted white J - K,
Tinted White L,
Tinted colors M to Z,
The color is graded by standard artificial light which is the equivalent of the Northern daylight.
Masterstones are used to compare color grading.
Cut :
The cut is determinate by 2 separate descriptions :
The proportions and the finishing grade.
These are the most important elements for the brightness of the diamond.
Clarity :
LC Loupe Clean. A diamond is called Loupe Clean after examination by an experienced grader with a
loupe of 10x
The following clarity grades are called Eye Clean or Cleanish and determined by the size, position, brightness and quantity of internal inclusions.They are measured by microscope.
VVS1 Very Very Small Inclusion 1 st degree.
VVS2 Very Very Small Inclusion 2 nd degree,
VS1 Very Small Inclusion 1 st degree,
VS2 Very Small Inclusion 2 nd degree,
SI1 Small Inclusion 1 st degree,
SI2 Small Inclusion 2 nd degree,
SI3 Small Inclusion 3 rd degree, New! SI3 is a split between SI2 and I1
The lowest clarity grades refer to inclusions that can be seen with the naked eye, by an experienced grader.
The grades are determined by the size, position, brightness and quantity of internal inclusions.
I1 Inclusion 1 st degree, I also indicated by P for pique.
I2 Inclusion 2 nd degree,
I3 Inclusion 3 rd degree,
Fluorescence : When diamonds are strong Fluorescent it can quote the color to a lower quality in facts of lower Color and Clarity.
Your diamond has the best quote: NIL (no fluorescence)
If the diamond is of a lower Color, slightly tinted White, the fluorescence can enhance the Color to White. (maximum medium fluorescence) Than it is a positive fact.
HPHT processed or hp-ht treatment of diamonds: truth value?
Diamond can be processed by High Temperature (HT) and High Pressure (HP) treatment to improve its appearance. It is a similar natural treatment as 3.3 billion years ago when nature create diamonds.
Only very rare diamonds type 2a are suitable for this color improvement. HPHT processed diamonds cost less. That gives you the possibility to buy a D color diamond for the price of a F color.
There is not one single difference between Diamonds from type 2A, who were processed by nature 3.3 billion years ago, and diamonds who are processed artificial HP-HT now. These Diamonds are very rare especial in big sizes. Learn more about HPHT treatment of diamonds
Buying diamonds you must look at first to what is the most visible, that's what is the most important:
A. The weight and the size expressed in Carat
B. The Cut, Brightness
C. The Color
D. The Clarity
E. The Fluorescence
Shape :
Some common diamond shapes are: Brilliant, Princess, Oval, Heart, Pear / Teardrop, Emerald, Marquise, , Flanders, Trillion, Radiant, Tapers and Baguette. You can find several other Fancy shapes like Horse, Butterfly and more.
What shapes do diamonds come in?
There are many diamond shapes. The most popular are:
It is the standard for all other diamond shapes. More than 75% of diamonds sold today are round brilliant diamonds. The round brilliant diamond displays most fire and scintillation of all cuts.
Princess diamonds: square cut diamond with 90 degree angles on each corner, 57 to 70 facets. The Princess Cut diamond is a young cut, designed for getting maximum brilliance from a square cut.
Oval diamonds: oval diamonds usually have 56 facets, similar to a round brilliant.
Pear diamonds also named Teardrop diamonds: pear shape is a combination of oval and marquise cuts with 37 facets.
Emerald diamonds: emerald cut diamonds contains 24 facets. They can be rectangular or square shaped. They have bevelled corners and step cut facets.Select a good clarity and color. because of the open shape. Emerald diamonds are cheaper than brilliant diamonds. The weight is less, you can spend more on quality. The Emerald cut is a very stunning noble cut.
Heart diamonds: the best shaped heart diamonds are cut with even lobes and a well-defined outline Heart shape diamonds are hard to find and are considered most sentimental of all diamond shapes.
Trillion diamonds also named Trilliant diamonds: triangular shaped diamond with 50 facets. This triangular cut is one of Antwerp special cut diamonds. A one carat trillion or trilliant diamond looks as large as a 1.50 Carat round brilliant diamond! A trillion or trilliant Diamond is a dazzling and versatile diamond shape whose uses are unlimited .It can be used in earrings, solitaires, wedding bands, necklaces, bracelets and pendants.
Flanders diamonds: square cut diamonds with 65 facets, recently developed cut in Antwerp
Radiant diamonds: radiant is cut in the shape of a rectangle with rounded corners.
Square cut diamonds: rectangular shape, using 65 facets.
Baguette diamonds: step cut in the shape of a small rectangular stone. It has a table and 8 facets at the top and 8 facets at the pavilion.
Cushion diamonds: antique cut, deep cut with large facets. Only available on special request.
Asscher diamonds: It has 74 facets.Asscher cut is a common square emerald cut diamond with concentric squares and 74 facets. In diamond grading reports it will be described as such. The demand for Asscher cut diamonds comes only from the USA
Taper diamonds: single step cut wich has 9 facets. A taper has a table and 8 facets at the top and 6 facets at the pavilion, two of them at a taper form of an arrow.
The educational department of the Antwerp Diamond High Council is the HRD Institute of Gemology.
Want a professional Diamond Course:
Antwerp Diamond Courses & Antwerp Gemology Courses Back to top
The HRD-Institute of Gemology is the educational department of the Antwerp Diamond High Council
It offers a range of highly qualified training programs in diamond grading and gemology:
1. Diamond Grading Course
Diamond Grading - Basic
Diamond Grading - Advanced
Diamond Grading - Extended
Diamond Loupe Week
2. Diamond Sorting Courses
Sorting of polished diamonds – small goods
Sorting of rough diamonds - basic
3. Gemology Program
Gemology
Gem Practice Advanced
4. Workshops
Information about these courses:
All further information on the complete courses offer can be obtained from:
Antwerp Diamond High Council
HRD-Institute of Gemology
Hoveniersstraat 22
B-2018 Antwerp Belgium Europe
Tel. + 32 3 222 07 01
Fax + 32 3 222 07 04
cathy.osan@hrd.be
ingrid.struyf@hrd.be
Send us a mail if you have any questions remaining. We will try to answer them to the best of our knowledge. E-mail us
CMR Rough & Polished Diamonds Wholesalers - brokers - Manufacturers - Cutters Inc./s.a. Ajediam,
(Antwerp Jewels & Diamond Manufacturers)
Member of the Diamond Office
Your trusty Diamond company with 5 C's: Carat, Color, Clarity, Cut & Confidence, Famous diamond cutters since 1985
International Diamond Center,
Antwerp World Diamond Center
Diamond Bourse Kring Ground Floor Room 006
BE-2018 Antwerpen Europe Belgium
Tel: +32 3 770 86 86 Mobile phone + 32 479 28 12 13
Fax: +32 3 770 86 86
Registered at the National Bank of Antwerp Diamond Companies under Licence 0478 926 810
48H delivery, no shipping nor insurance charges!
60 days money back
Lifetime buyback - Find out how it is possible Click here
Customer Total Satisfaction Program
CMR Inc. n.v. Ajediam is specialized in big Diamonds, loose Gem-stones, Rubies, Emeralds, Sapphires and fine customized Diamond Jewelry, Diamond Rings, Diamond Earrings, Diamond Necklaces, Diamond Bracelets and more
We guarantee that all our diamonds are conflict-free, purchased from legitimate sources not involved in funding conflict in compliance with United Nations Resolutions.