What is the difference between VS and SI Diamond Clarity

What is the difference between VS and SI Diamond Clarity

Posted by SA. Khan & Claire on 19th Jun 2019

Bottom Line...

  • GIA Graded VS1 and VS2 diamonds very high clarity grades. They should always be considered eye-clean to the naked eye. 
  • The larger the diamond, the more visible the inclusions. Therefore, VS2 diamonds in above 2.5 carat range should be carefully inspected. 
  • SI1 should be considered eye-clean in the 1 carat range. It can be eye-clean in the 2 carat range depending where the inclusions are located and type of inclusions. Follow our diamond clarity guide carefully for through examination. 
  • SI2 is a decent clarity grade in the 1 carat range, but should not be expected to be eye-clean in above 1.5 carat weight diamonds. If you are lucky, you might find SI2 carat diamonds in the 1 carat range that is 95-99% eye-clean. 
  • While VS1/VS2 are good investment grade ranges, SI1/SI2 are great budget options. 
  • Use Jame Allen's Ultra HD 3D Technology to assess the location and size/color of inclusions before purchasing the stone in order to make an informed decision. Usually large black crystals in the center of the diamond should be avoided. Also, avoid SI1/SI2 diamonds the clarity grade of which is based on clouds (look at the comments section of the GIA report and if it states "clarity grade based on clouds" avoid that diamond as it will look dull). 

GIA Diamond Clarity Scale

Diamond Clarity – Overview...

The clarity of a diamond refers to how clean a diamond really is. Mostly all diamonds, both mined and lab-grown, have inclusions of some type. These inclusions are imperfections that work to create uniqueness in each diamond. Too large an inclusion causes the diamond to have a lower clarity rating, and this could affect the value and quality of the diamond.

The inclusions in a diamond could be a number of things, such as crystals, clouds, trace minerals or feathers. They are usually very small if apparent at all but placed in an obvious position they can be quite noticeable.

When it comes to purchasing a diamond, the higher clarity, or flawless diamonds, are the most valuable and will have a much higher price. The lower down you go on the clarity scale, the less you will pay for a diamond. If you are sticking to a budget, it would at first make sense to choose a lower clarity diamond. However, it should be kept in mind that if an inclusion or blemish is too pronounced, it could negatively affect the brilliance or sparkle of a diamond.


The Diamond Clarity Grade...

All loose diamonds are graded on a clarity scale which takes into consideration the size, number, and type of inclusions. This scale was created by the Gemological Institute of America (GIA). There are six categories in the grading scale and eleven diamond clarity grades. The scale ranges from FL and IF, which are Flawless or Internally Flawless, to I, which is Included. FL and IF diamonds have no visible inclusions or imperfections when viewed under 10x magnification. I diamonds have inclusions which are easily viewed with the naked eye.

Finding a balance between these two grades will help you fit the diamond you want into your budget, but still allow you to buy a diamond which is visually appealing and which still has a wonderful sparkle.

VS vs SI diamonds...

Choosing a diamond graded as SI or VS is a good idea if you are wanting to make the most of your diamond budget. Both these grades of diamonds are clean to the naked eye and have almost no visible difference when looked at.

VS diamonds can be graded as VS1 or VS2. These diamonds are Very Slightly included and have inclusions which can be viewed with a 10x magnification. These fall third on the grading scale are regarded as good quality diamonds and you should not notice any blemishes or inclusions in the diamond when they are set.

SI diamonds can either be graded as SI1 or SI2. They are rated fourth on the diamond clarity scale and are Slightly Included. These inclusions can easily be seen using 10x magnification but most often cannot be noticed with the naked eye through the crown of the diamond. However in some cases, depending on where the inclusion is based, it might be slightly noticeable by the naked eye. These are fair quality diamonds to purchase and can save you a great amount when trying to fit a diamond into your budget.

It is usually recommended not to go below a VS diamond, but if you find an SI diamond which is clean to the naked eye, you can really gain maximum value from purchasing this diamond. An SI1 diamond which is visibly clear to the eye will seem almost identical to a VS diamond but will be a cheaper option to purchase. Due to this, it is a good idea to buy an SI1 diamond, which is clear to the eye.

It will be worth your while to search for an SI1 diamond which you are happy with. Not all SI diamonds are visibly similar, some might have a haziness that is apparent with magnification while others might have a slight haziness which can be seen with the naked eye. Compare diamonds together to be able to make the right choice.

James Allen

Clarity Grading Factors...

There are five different factors that can have an effect on the clarity of the diamond, these factors are size, nature, number, relief, and location.

Size – The larger the inclusion in the diamond, the lower the clarity grade will be. A large inclusion can also have an impact on the durability of the diamond, which is why a lower grade diamond should not be bought.

Nature – Nature refers to what type of inclusion it is and takes into consideration the depth of the inclusion. Inclusions are flaws which penetrate deep within the diamond, whereas blemishes are flaws that do not penetrate the diamond but are instead confined to the surface of the stone.

Number – The number of inclusions is important, as the larger the number of inclusions or blemishes, the lower clarity grade of the diamond will be. However, if the inclusions are not visible, it will not have an impact on the overall number rating.

Location – The location refers to the position of the inclusion or blemish in the diamond. The closer the inclusion is to the center of the table, the more effect it will have on the clarity. This is because it interferes with the way light reflects within the diamond. Inclusions closer to the girdle are difficult to see, but if they are close to the surface they could damage the stone.

Relief – Relief is the distinctness of the inclusion when viewed within the diamond. Therefore the greater the relief, the larger the effect on the clarity grade.

The Importance of Clarity...

While all of the 4C’s, clarity, cutcolor and carat should be taken into consideration when buying a diamond, clarity should be one of the main deciding factors. Going below an SI1 diamond runs the risk of you purchasing a diamond with a visible inclusion, which could affect the overall sparkle and brilliance of the diamond or you purchasing a diamond with an inclusion that might affect the durability of the stone.

If you are battling to decide between a VS and SI diamond, it might be a better idea to go for an SI1 diamond. Finding an SI1 diamond which is clean to the eye will help you save a significant amount on your budget and you will still be left with a beautiful sparkling diamond that will look gorgeous in any setting.