Diamond Rocks UK Logo

Diamond Clarity

The clarity of a diamond refers to the internal and external marks that can occur while the stone is formed, but many of these are totally unnoticeable to the naked eye.

Watch our video below for an overview of diamond clarity.



A perfect diamond is classed as Flawless as there are no scratches on the surface – known as inclusions – nor are there any imperfections inside it.  These are referred to as inclusions and are the result of the diamond having specks of different materials in them.

Below this top grade of diamond are Internally Flawless ones, which may have slight blemishes on the surface, but again, these can't be seen under normal conditions.

From there downwards, there are Very, Very Slightly included (VVS1-2), Very Slightly Included (VS1-2) and Slightly Included (SI1-2) – each of these have two sub-grades to help differentiate them further.

These are decided by a skilled grader who uses ten-times magnification to check the diamonds, with the grade playing a part in how much the diamond costs. There is a further category – included diamonds – but these are of too low a quality for us to stock, as their brilliance could be affected by the inclusions.

When it comes to diamond clarity there are eight different types of flaws that could be classified within each unique diamond:

  • External Diamond Flaws: Also known as blemishes, these types of flaws would include cuts, nicks, polishing lines and pits that would be visible on the outside of the diamond. Sometimes these can be polished down or can be cut to remove the flaw from the naked eye.
  • Internal Diamond Flaws: Also known as inclusions, these flaws can sometimes be serious or minor depending on the way that the light will interpret the flaw when reflected. What matters the most is that internal flaws can greatly depreciate the value of the diamond.
  • Cleavage and Feathering: Also known as the cracks that are found inside the diamond, cleaving would not have feathers which will affect the overall strength of a diamond. If the crack does have feathering then the diamond is not compromised in strength unless it has reached the outside of the stone.
  • Pinpoint Inclusions: Small, tiny crystals that form within the diamond are known as pinpoint inclusions. If formed in clusters they could cause a clouding effect inside the diamond and affect the way the diamond will sparkle.
  • Grain Lines: Irregular lines that form within diamond which could be clear, coloured or white. Clear lines will not affect the grade of the diamond.
  • Bearding: After a diamond is cut there might be occasions where small lines would appear around the girdle of the stone. This would be called bearding. These lines can be polished or the diamond could be re-cut so they are removed.
  • Laser treated: Laser treatment could improve the diamond clarity. This would affect the grade of the stone and can sometimes be seen by the naked eye in the form of a jet stream or light trail.
  • Crystal and Mineral Inclusions: Diamonds sometimes have crystals that will be embedded within them which for some people ads character to the diamond. Not all will negatively affect the pricing of diamond jewellery, so it will depend on what imperfections you find, the diamond itself can still have incredible value.

Pick the clarity of diamond to suit your budget today by browsing the Diamond Rocks website.  Watch GIA's own video guide to diamond clarity below.

Learn about the 4C's

Carat, Colour, ClarityCut.

This website is using cookies. More info. That's Fine