Inclusions are the internal flaws that are caused because of foreign material which is introduced while the diamond is forming. Blemishes occur during either the cutting process or general wear and tear on the diamond. When you are determining the value of a diamond, the inclusions are more of a factor than any blemished.

There are a variety of different foreign materials which could harm the clarity of a diamond, minerals penetrating the diamond during formation, small crystals, and small cracks known as feathers. There are also surface blemishes, but these affect the overall value of a diamond much less than the inclusions. Most surface blemishes can be removed during the cutting and polishing process.

There are two main reasons why it is necessary to test and label the clarity of diamonds. The first reason is one of most important in regards to the quality of brightness and fire inside the diamond; this is the aesthetic, the level of transparency. The second reason is the overall safety of the diamond, whether or not the flaws could cause the diamond to break.

Most blemishes or inclusions pose very little threat to the brightness or fire of the diamond, but there are certain types of inclusions which could affect a diamond. Some of the serious inclusions are large chips or cavities, a feather that extends deeply into the diamond, or in very rare cases, a knot of included crystal that extends all the way to the surface of the diamond. These types of inclusions may not affect the fire and brightness of a diamond, but they could cause the diamond to become fragile and break. If you see any of these inclusions listed on the gemological certificate, your best option is to avoid purchasing it.

How is Diamond Clarity Graded?

To determine the precise clarity of a diamond, it has to undergo a thorough gemological examination. They will conduct a diamond clarity test under precise laboratory conditions, utilizing detailed guidelines. The first things that they will ensure is that the diamond is a loose diamond, and not set in any jewelry, which could hide some of the inclusions. The basic examination is done by evaluating the diamond from face-up with a microscope that has a magnification power of at least 10X. Afterwards, the diamond is examined from different angles, and if needed, under higher magnification.

Once they have undertaken this detailed evaluation, the clarity of a diamond is determined by five criteria:

• Size – Depending on how large any inclusions are, they will be then graded, the larger they are, the lower the clarity of the diamond.
  
  
• Number – In most cases, the more inclusions there are, the lower the clarity of the diamond is. However, smaller inclusions won’t necessarily affect the clarity grade as much as more, larger inclusions could.
  
  
• Position – The position of any inclusions is very important to the clarity grade. If the inclusion is positioned underneath the table, it will be much more visible, compared to if it was positioned underneath the facets. If an inclusion is positioned near a ‘strategic’ part of the diamond, it could be more likely to cause it to break.
  
  
• Nature – This is the severity of the inclusion, and whether or not it is either internal or external. Any large breaks in the stone or feathers, especially those that reach the table or extend from the crown to the girdle pose a serious threat to the durability of the diamond and will significantly lower the clarity grade.
  
  
• Relief – This is the contrast or visibility of the inclusion inside the diamond. Most inclusions are white or colorless, but they can also be black, dark red, green or brown. The inclusions that are dark in color are more visible than the lighter colors, and therefore lower the clarity grade of the diamond.
  
  

Once all of these examinations are complete, the clarity of the diamond will be assigned. The better or higher a clarity grade is, the more expensive the diamond will be! If a diamond doesn’t have any inclusions, either internal, or external, it is considered “Flawless”, but these diamonds are the rarest of all diamonds.

The clarity grades of diamonds descending from Flawless are listed as follows:

• Internally Flawless (IF) – This is a diamond with no internal inclusions and only very insignificant blemishes.
  
  
• Very, Very Slightly Included 1 & 2 (VVS1, VVS2) – These are diamonds containing only minute inclusions, ranging from extremely difficult (VVS1) to very difficult (VVS2) for a skilled grader to see under 10X magnification.
  
  
• Very Slightly Included 1 & 2 (VS1, VS2) – A diamond-containing only minor inclusions that are difficult (VS1) to somewhat easy (VS2) for a trained grader to see under 10X magnification.
  
  
• Slightly Included 1 & 2 (SI1, SI2) – This is diamonds which contain noticeable inclusions that range from easy (SI1) to very easy (SI2) for a trained grader to see under 10X magnification.
  
  
• Included 1, 2 & 3 (I1, I2 & I3) – Diamonds that contain obvious inclusions to a trained grader under 10X magnification. I1 diamonds have inclusions that are usually quite visible to the naked eye. In I2 diamonds the inclusions are easily visible and in I3 diamonds the inclusions are extremely easy to see and may affect the durability of the diamond.
  
  

Details You Should Know About Diamond Clarity

The diamond scale used above is the work of the GIA, the Gemological Institute of America. They first published this grading scale in 1953, and it has changed very little since it was published. Different laboratories may choose to use different grading scales, but this is the most popular and renowned around the world.

Only 20% of the diamonds found in the world match the needs of the jewelry industry; the rest are used in a variety of mechanical and industrial needs. A large majority of those 20% of diamonds used in jewelry have eye-visible inclusions before the diamond is set into jewelry.

Based off of these numbers, it is easy to determine that there aren’t many flawless diamonds, making them very expensive! There are always people in the diamond industry who will try and talk you into choosing a flawless diamond, but often the price is much too high to justify. Many diamonds that have inclusions aren’t even visible until you place them at high levels of magnification. In a lot of cases, people can set diamonds with visible inclusions into jewelry cleverly to help disguise them, making them a popular choice if your budget is lower.

Choose the type of diamond you want to purchase carefully, based on your needs. Another thing to remember is that inclusion in a diamond is an easy way to tell if your diamond is real, compared to a perfect synthetic diamond.