1. The 8 Quality Criteria
Private Diamond Club

2. The 8 Quality Criteria
While the beauty of an visual attraction to a precisely cut stone can vary from one person to another, the actual value is based on well defined international standards.

4. 1. CARAT (THE WEIGHT) - 1 CARAT EQUALS 0,2 GRAM
(please note that the actual size may vary due to different screen resolutions)
The price per carat is the not the same regardless of the weight of the stone: i.e. that a 2 carat stone price is much higher than 2 stones of 1 carat each, 7 other criteria being the same.
In other words, the higher the weight of a stone, the higher the price per carat is.

5. 2. CLARITY
Clarity grades are determined by the size, position, brightness and number of inclusions.
Private Diamond Club only sells diamonds ( loose or set as a jewel ) with clarity grade from IF to SI2  and in no case lower gradations such as P1 - P2 ...

6. 3. COLOR 
(Please note that this image is only meant to show the different shades, real diamonds can look different)
Private Diamond Club only sells diamonds (loose or set as a jewel) with Color between D to H and in no case lower color stones such as I - J. ...

7. 4. SHAPE
The most common shape is the round one or "brilliant cut". With 57 facets it is the form that returns the most light and is the best selling and most expensive.
Other shapes called "fantasy" are used in jewelry as the princess cut, heart, marquise, emerald cut, drop, cushion, oval etc. ....

8. 5. PROPORTIONS 
Each diamond shape must meet specific characteristics of proportions between its different facets to reflect and diffract light optimally.
Private Diamond Club only sells diamonds (alone or set on a jewel) whose proportions are "Excellent" or "Very good". With lower gradations, the value of the diamond drops from 10 to 30%.

10. 6. SYMMETRY
Similarly, the dimensions of facets and angles they form between themselves must be perfectly balanced to give the stone its maximum brightness.
Private Diamond Club only sells diamonds (alone or set on a jewel) whose symmetry is "Excellent" or "Very good". With lower gradations, the value of the diamond drops from 10 to 30%.

11. 7. FINISH
No imperfections resulting from the size, no trace of rough diamond on the facets must not stand to avoid any obstacles in the path of the light.
Private Diamond Club only sells diamonds (alone or set on a jewel) whose finish is "Excellent" or "Very good". With lower gradations, the value of the diamond drops from 10 to 30%.

12. 8. FLUORESCENCE
Contrary to what one might think, the most common diamonds are fluorescent and the rarest are not.
Private Diamond Club only sells diamonds (alone or set on a jewel) whose Fluorescence is "Nil" or " Faint". With lower gradations, the value of the diamond drops from 10 to 30%.

13. CONCLUSION
The higher is the rank of the stone in all of these categories, the greater is its value. Official certificates (issued by HRD, GIA or IGI), which must accompany each diamond, refer to these eight quality criteria.
The certification of the diamonds is the best way to guarantee the purchaser the authenticity and quality of the diamond.
We emphasize that the 4 criteria " 4 C's" are not sufficient to characterize a diamond  and it is of major importance to specify the gradations of the 4 other quality criteria which are, alas, too often ignored.