Diamond appraisals grading ratings course

Appraisal Valuation..  One minute diamond course for free… Four C’s Diamond Quality Grading Chart – Diamond Characteristics & Specifications, valuation.

View the 997,920 quality variations of diamonds in a chart

Highest to lowest actual quality specifications by importance: cut, carat, color, clarity – tips & tricks (dirty) – appraisal, valuation. Educational tools + ratio to find the perfect diamond by quality specification defined by importance

1. Cut: Ideal -Triple Excellent – Hearts & Arrows
2. Carat Weight
3. Carat Size
4. Color Blue – White Color
5. Clarity 6. Fluorescence

Understand determining qualities, produced by international diamond grading certificates before purchasing. Diamond grading is an opinion covering some aspects of diamond qualities, named the 4C’s, but that is not all you must know, understand all.

Each diamond is individual and each individual diamond is different! Perception of quality, tips, and tricks – avoid the scams!

Antwerp World Diamond Center, World’s largest Diamond Trade Center with a yearly turnover of more than 56 billion US $

How to buy diamonds – what characteristics are important to the quality and the influence on the price:

Avoid buying bad quality, fake and simulant diamonds – read about: dirty tips and tricks Official appraisal, valuation.

1. 4C’s, in fact, 8C’s The essential most important knowledge about diamonds

Cut grading chart

The 1st criterion is the Brightness: The ideal cut, Triple Excellent, Hearts & Arrows is by far the most important matter
buying diamonds! You see it. Your Diamond has the best Brightness or not
On the Diamond Certificate you must find following grading: Cut grade:
Proportions: Hearts & Arrows, Excellent, Very Good, Good, Fair, Poor, Unusual or Fancy cut
Polish: Excellent, Very Good, Good, Fair, Poor
Symmetry: Excellent, Very Good, Good, Fair, Poor, Unusual Brightness is obtained by the art of Cutting and Polishing View ideal proportions all shapes Ideal cut: H&A

2. Carat weight grading chart The 2nth criterion is the weight of the diamond. Carat weight converted in milligrams and grams. You can see it.
Your Diamond is big or small ! (Weight is expressed in Carat) View diamond Carat weight

3.  Diamond sizes The size of diamonds Dimensions expressed in millimeter and centimeter. The size is determined by shape and cut

4. Color grading chart   The 3rd criterion is the Color:  You can see it.
Your Diamond is White. (D, E, F, G, H, I are White Color indications) D, E, F – Blue White registered color explained

5. Clarity grading chart  The 4th criterion is the 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.

6. Fluorescence  The 5th criterion is the Fluorescence, read more about

We describe the four most important quality requirements,

4C’s. in fact 8C’s for diamonds: Cut, Carat, Color, Clarity and morefor diamonds: Cut, Carat, Color, Clarity and more

1. View Cut grading chart – Cut is most important to diamond valuation – View images
Cut and shape are frequently confused.
Shape is the model
Cut refers to the quality of Cut, Proportions, By the finishing grade

The loss in carat weight between a rough and cut / polished diamonds is about 60 to 66 %
Example: a rough diamond of 2.00 Carats gives a cut and polished diamond with ideal cut of about 0.66 carat

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. Read more about

2. Carat grading chart – View images:
There are 2 separate definitions: The diamond carat size and the carat weight of diamonds Each diamond has an individual weight, depending on the cut and the shape. The diamond weight is expressed in Carats. One Carat has a weight of 200 milligram – 200 milligrams = 0.2 grams.

3. Diamond size is generally measured by the diameter on the girdle of the shaped diamond.

4a. Color grading chart – View images:
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: Read more about and view the color grading chart

4b. Fancy color grading chart – view images:
Blue, Black, Pink, Champaign, Canary Yellow, Cognac and Green exist in natural color or enhanced by treatments
The color is graded by standard artificial light which is the equivalent of the Northern daylight.
Masterstones are used to compare color grading. Visualize colored diamonds grading in all rainbow colors

5. Clarity grading chart – View pictures
Defining the existence of visual inclusions, impurities of external and internal characteristics of a diamond. visualize clarity grading chart

6. Fluorescence influencing color explained The mysterious “Blue White” registered Color explained

HPHT processed or hp-ht treatment of diamonds: genuine value?

Buying diamonds you must look at first to what is the most visible, that’s what is the most important:

1. Ideal Cut, Triple Excellent, Hearts & Arrows = Brightness
2. Carat – weight and the size expressed in Carats
3. Size – expressed in dimensions
4. Color
5. Clarity
6. Fluorescence

Shape :
Some common diamond shapes are: Brilliant, Princess, Oval, Heart, Pear / Teardrop, Emerald, Marquise, Flanders, Trilliant – 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:

Brilliant cut + shape: visualize facets
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 cut + shape: square cut diamond with 90 degree angles on each corner, visualize facets. The Princess Cut diamond is a young cut, designed for getting maximum brilliance from a square cut.

Marquise cut + shape: visualize facets

Oval cut + shape: oval diamonds are similar to round brilliant diamonds. visualize facets

Pear cut + shape: also named Teardrop diamonds: pear shape is a combination of oval and marquise cuts. visualize facets

Emerald cut + shape: They can be rectangular or square shaped. They have beveled 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. visualize facets

Heart cut + shape: 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. visualize facets

Trillion – Trilliant cut + shape:also named Trilliant diamonds: triangular shaped diamond. 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. visualize facets

Radiant cut + shape: are square cut diamonds rectangle with rounded corners. visualize facets

Square cut diamonds: rectangular shape. Visualize facets

Cushion cut + shape: Deep cut with large facets. Very good shape for color diamonds because of the depth. visualize facets

Asscher cut + shape: Is a common square emerald cut diamond with concentric squares. In diamond grading reports it will be described as such. The Asscher cut diamond was created by the Asscher brothers of Amsterdam, Holland (Netherlands) in 1902. Square cut diamond such as emerald… but with less facets = less fire and brilliance. Other inconvenient: flaws and inclusions are easy to see. visualize facets

Flanders cut + shape: square cut diamonds with 65 facets, recently developed cut in Antwerp

Baguette cut + shape: 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.

Taper cut + shape: single step cut which 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.

Avoid buying bad quality, – Tips and Tricks, (dirty) – Learn how to detect fake and simulant diamonds

  • Poor cuts (even the D IF ‘graded’/indicated ones), also called off-makes, are relatively cheap! You may find these offered at eBay and tourist trap shops. A poor cut diamond has up to 50% less brilliance than a Very Good cut diamond. Poorly cut diamonds will refract only white light, or appear dull and lifeless and often have dark or washed-out areas that allow to see through the bottom of the stone.  Watch out: … Purchasing a diamond online is like buying a second hand car without a test-drive …
  • The lighting at tourist shops (and many jewelers) is specialized to enhance the brilliance and whiteness of a diamond. Watch out: a diamond appears much whiter than it really is in such a lighting condition.
  • Tourist and (online) diamond shops frequently use fake certificates to sell a diamond to you.
  • Watch out: switching a certificate for one with a better grade also occurs!
  • Too thin girdle diamonds: Yes, a diamond can break or be chipped. You better avoid these very thin girdle diamonds (despite the fact that they are cheaper) frequently offered online.
  • Doublets: Doublet is a composite of a diamond and a simulant. The top (1/3) is true diamond, the bottom 2/3 worthless zircon or another simulant. The tourist trap jewelry shop may demonstrate to you with a diamond tester (the top and only genuine part) that it is true diamond. Watch out: you’ll end up always paying the diamond price for the simulant bottom part!
  • Other diamond tricks, like treated diamonds nowadays quite popular in online auctions!  Good to know yet very difficult to notice: high-pressure high-temperature treated diamonds (brittle),
  • laser drilled diamonds
  • Detect fake / false certificates
  • coated diamonds
  • stimulants
  • paying handling costs for returning a diamond purchased online and/or
  • paying for damaging the original (sealed) packaging,
  • glued diamonds,
  • fracture-filled diamonds,
  • irradiated fancy colored diamonds.
  • Diamond watches online offers trick: Look for small sentence like “All custom diamond and gold work is done by …, and not by the watch manufacturer. This means the diamonds are NOT set by the watch manufacturer and you have NO manufacturer’s warranty.
  • Ask for a real buyback guarantee!

Learn about Diamond certificates Discover and learn about all diamond resources

Learn about Jewelry, settings, materials, precious metals and more Learn about Jewelry care + cleaners

Learn about Diamond wholesale prices + appraisals

Understanding HPHT Diamonds. Read more about

Detect real diamonds from fakes

How releable are diamond testers? Find out

Want a professional Diamond Course:

Antwerp Diamond Courses & Antwerp Gemology Courses

Diamond High Council – HRD professional Diamond Courses
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
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

ISG training programs please visit the ISG website at
The International School of Gemology is a Certified Continuing Education Provider for the Texas Department of Insurance. Mail to:

Email if you have any questions remaining. We will try to answer them to the best of our knowledge.