diamonds, carat, cut, clarity, color 4 c's,

Diamond quality standards: 4 C's

 

Diamond color grade letters

Cut

Diamonds have to meet certain quality standards. Since the 15th century it was known that a diamond had to be cut in a certain way to add the "fire" and "shine" to it.The cut of a diamond refers to internal relationships and the way a diamond is cut. It was the famous grinder Tolkowsky who defined the certain mathematical relationships to maximize the sparkle. When the light falls trough the table of the stone, the light is again being emitted through his facets. From a rough diamond different forms can be cut. The most common cut shapes are:

 

  • Brilliant (classic round) 
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  • fantasy cut diamond examples
  • Marquise
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  • Pear
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  • Oval
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  • Baguette
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  • Princess

(This list is far from complete as there are numerous cuts and variations)

Carat

The weight of diamonds is shown in Carat and is internationally accepted. The weight of diamond is expressed in metric carat - 1 carat = 0,20 gram. 

Clarity

From the inclusions we can recognize a specific diamond, it is actually the fingerprint of a diamond. The purity of a diamond is always determined by a magnification factor of 10.
 

The clarity of the diamond can be influenced by two types of impurities:

  1. EXTERNAL impurities: these are surface impurities due to wear and tear caused by use or damage during grinding.
  2. INTERNAL impurities: impurities that reside inside the stone. Some examples :
  • Spots: dark stains that arise in the carbon.
  • Clouds: Groups of inclusions that weaken the brightness  
  • Feathers or feather: most of the impurities in the stones come from a molecular fraction in the building of the carbon structure of the diamond

There are different categories of purity: (degrading list)

clarity grade example

  • • Clear/Internally flawless (IF) : no impurities to determine
    • VVS : very very small impurities, identified only by professional
    • VS : very small impurities, barely / not recognized by non-professionals
    • SI : visible impurities recognized by non-professionals
    • Pique : impurities even visible without magnification

Colour

The colour of a diamond is very important.  Colour table. 

Diamond color card

 

D: Exceptional White (Jager)

E: Exceptional White (River)

F: Rare White  (River)

G: Rare White (Top Wesselton)

H: White (Wesselton)

I-J: Slightly tinted white (Top Crystal/Crystal)
 

For bigger diamonds,  like 0.50 ct, you can request a certificate.
The certificates are delivered by an indepentent Institute (HRD, EGL, IGI).