Diamond Cut


Diamond Cut:

It takes a painstaking amount of work, to make diamonds as beautiful as you’ll see in their polished life, as they start out as an uneven natural state called a ‘rough.’ Every other aspect of the diamond is an act of nature; however, the cut is the only part of diamond creation that requires a human input. It’s the most important, yet the most misunderstood part of the process. Diamond cutting is an art and it can take weeks to produce the perfect outcome.

Cutting is so important because it unlocks a diamond’s beauty and sparkle. A perfectly cut diamond will be so eye-catching thanks to its brightness, fire and scintillation. 

Brilliance, Polish and Symmetry of a Diamond

The Cut of a diamond produces its Brilliance (reflection of light), whereas Polish (smoothness of facets) and Symmetry (alignment of facets) affect the sparkle of a diamond. A poor polish can make a diamond look dull and a poor symmetry can misdirect the light reducing the sparkle or creating a strange appearance in the stone.

Types of Cut:

There are three types of cuts as shown in the figure:

Shallow Cut:


If a diamond is cut too shallow, the light will disappear through the bottom of the stone.

Ideal Cut 


If a diamond has an ideal cut it means the angles are perfect for the performance of light and the light will come back through the top of the diamond

Deep Cut



If a diamond is a deep cut. The light will not make it back to the top of the stone it will be lost out the side and will look flat and lifeless.

GIA Cut Grading

Diamond cuts are graded on the following scale established by the Gemmological Institute of America (GIA):

  • Excellent Cut: The rarest cut grade of all, Excellent cut stones reflect the maximum light entering the diamond and they will shine with optimum brilliance.
  • Very Good Cut: Very Good cut grade is close to perfect, but some small angles may be slightly off, affecting the light performance marginally.
  • Good Cut: Good cut grade of a diamond helps reflect light to obtain a good amount of brilliance, though not equal to the Excellent or Very Good cut. 
  • Fair Cut: Being not as brilliant as a Good cut, Fair cut grade quality diamonds refract less amount of light but make a better choice than Poor cut diamonds.

Diamond Dimensions

The various dimensions of a diamond are defined as follows:

  • Table : The topmost and largest facet of a diamond.
  • Crown: The sloping section of a diamond- from the girdle to the table.
  • Girdle: The point where the crown and pavilion meet, which also determines the perimeter of the diamond.
  • Diameter: The width of the diamond measured with reference to the girdle.
  • Pavilion: The lower section of a diamond from the girdle to the culet.
  • Culet: The tip of a diamond (the best culet is invisible to the naked eye).
  • Depth: The height of a diamond measured from the culet to the table.


Starfire Diamond Jewellery Ideal Cut Grade

At Starfire we pride ourselves in providing extremely high-quality diamonds. We stock no less than Ex-VG cut stones and see the cut as one of the leading factors that should be considered when purchasing a stone.