About The 4 C's

A larger carat weight means a bigger diamond. However, it is important to note that a 2 carat diamond is not twice the size of a 1 carat diamond. Diamonds with a similar carat weight may have different measurements, which might affect the appearance of the diamond. Diamonds which have a fancy cut might also appear as larger, for example a marquise cut will look much bigger than a round brilliant cut - even if both diamonds have the same carat weight. 

Carat does not necessarily affect the value of a diamond, but larger diamonds are much more rare and desirable and therefore cost more. With lab grown diamonds, it is possible to purchase a larger carat weight with more desirable qualities, at a much more affordable price. 

Diamonds are graded under controlled lighting in precise conditions. This is because the colour differences may be very subtle, but these distinctions make a big difference in the overall diamond quality and price. 

Fancy coloured diamonds are assessed using a slightly different system. Coloured diamonds come in shades of yellow, orange, brown, pink, blue, green, red, purple or black. Coloured diamonds are graded using 3 different points; the hue (the actual colour), the tone (lightness or darkness of the colour), and the saturation (how strong or weak the colour is). 

Diamond fluorescence is also recorded in diamond reports. Fluorescence is a soft glow that some diamonds might show when exposed to ultraviolet rays (UV). Diamonds might show a blue glow, or sometimes an orange or yellow glow. When the UV light is removed, the diamond will stop fluorescing.

The fluorescence of a diamond is graded by intensity; None, Faint, Medium, Strong and Very Strong. Fluorescence may affect the price of the diamond. 

• D-E (River):
  Colourless or Rarest White
  
• F-G (Top Wesselton):
  Near Colourless or Rare White
  
• H (Wesselton):
  Near Colourless or White
  
• I (Top Crystal):
  Faintly Coloured
  
• J (Crystal):
  Faintly Coloured
  
• K-L (Top Cape):
  Slightly Coloured
  
• M-N (Cape):
  Slightly Yellowish
  
• O, P, Q, R (Light Yellow):
  Yellowish
  
• S-Z (Yellow):
  Yellow
  

• Flawless - FL:
  The diamond has no inclusions or blemishes visible under 10x magnification. A totally clean diamond inside and outside.
  
• Internally Flawless - IF:
  No visible inclusions inside the diamond. There might be tiny blemishes on the outside of the diamond.
  
• Very, Very Slightly Included (VVS1 & VVS2):
  Inclusions are so slight that they are difficult to be seen even under 10x magnification.
  
• Very Slightly Included 1 (VS1):
  The diamond has minor inclusions that are observed with effort under 10x magnification and are usually colourless.
  
• Very Slightly Included 2 (VS2):
  Inclusions are usually minor, but may be darker in colour or may be situated in the table area of the diamond. These inclusions are still characterised as minor.
  
• Slightly Included 1 (SI1):
  Inclusions are noticeable under 10x magnification. These inclusions are still somewhat hard to notice with the naked eye.
  
• Slightly Included 2 (SI2):
  Inclusions are noticeable under 10x magnification and are somewhat noticeable with the naked eye. These inclusions don't affect the brilliance too much.
  
• Included 1 (I1):
  Inclusions are obvious under magnification and with the naked eye, and are usually quite large.
  
• Included 2-3 (I2-I3):
  The diamond has really large inclusions which can be seen with the naked eye, and they may affect the transparency, brilliance and beauty of the diamond.

• Excellent: This is the highest cut grade. The diamond is well proportioned and the light is distributed evenly throughout the diamond. 

• Very Good: The majority of light is still reflected through the top (crown) of the diamond.

• Good: A good amount of light is still reflected, but it will not appear as brilliant as a higher cut grade.

• Fair: These diamonds do not have the correct proportions, which causes a loss of light out of the bottom of the diamond. The diamond might appear darker than higher cut grades. 

• Poor: This is the lowest cut grade. These diamonds often appear dull and dark. 

If a diamond is cut too shallow, light escapes from the sides and the overall brilliance of the diamond is lost. If the diamond is cut too deep, light escapes form the bottom and the diamond might appear dull or dark. 

Improper symmetry include facets which are not properly aligned, poorly shaped facets, off-centre culet or an off-centre table.

After a diamond is cut and faceted, it must be polished. This process might leave scratches or marks, which can affect the overall quality of a diamond, and it will affect the cut grade.

A diamond which has excellent proportion, symmetry and polish will have three different qualities known as scintillation, fire and brilliance. When the diamond is moved, the flashes of light from facet to facet towards the diamond centre is called scintillation.

Light travels into the diamond and some of the light rays are divided into flashes of different colours, this is called diamond fire or dispersion.

Lastly, brilliance is the white light which is reflected off of a diamond.