SI1 Clarity Grade Diamonds

SI1 Clarity Grade Diamonds

As we know, the price of a diamond is directly correlated to the 4 C’s – Carat Weight, Colour Grade, Clarity Grade, and the Cut Grade (i.e. the shape of the diamond). Though there are other important factors that we advise our clients to pay attention to, these four have the largest impact on price.

A diamond’s clarity grade refers to the inclusions present in the diamond. What does this mean? Let’s take a quick geology lesson.

A diamond requires the following to be formed:

  • Carbon
  • Consistent Pressure
  • Consistent Temperature
  • Time | Millions of Years

During the formation process, if there are even minor changes to any of the above, the diamond develops an inclusion – sometimes referred to as a ‘clarity characteristic.’ There are different types of inclusions, and depending on the number and the degree of visibility, the Gemological Institute of America (GIA) certifies diamond clarity grades in the following manner: 

No Visible Inclusions | 100% of the time
Internally Flawless
No Visible Inclusions | 100% of the time
Very Very Slightly Included | Level 1
No Visible Inclusions | 100% of the time
Very Very Slightly Included | Level 2
No Visible Inclusions | 100% of the time
Very Slightly Included | Level 1
No Visible Inclusions | 100% of the time
Very Slightly Included | Level 2
No Visible Inclusions | 85% of the time
Slightly Included | Level 1
No Visible Inclusions | 30% of the time
Slightly Included | Level 2
No Visible Inclusions | 10% of the time
Included | Level 1
Inclusions Likely Visible | Not Recommended
Included | Level 2
Inclusions Likely Visible | Not Recommended
Included | Level 3
Inclusions Likely Visible | Not Recommended


Further Reading on Diamond Clarity from the Gemological Institute of America:

SI1 Clarity Diamonds

Let’s take a deep dive on one particular clarity grade  – the SI1.

Our gemologist believes that this clarity grade has always been the secret to getting the best value for money. You see, when we look at a diamond, the two most noticeable features are the size and the colour of the diamond. By fine-tuning our search for an SI1 clarity grade diamond that has no visible inclusions, we can opt for either a larger size diamond, a better colour grade, or just hold on to the savings!

So, how do we know if the SI1 Clarity Grade diamond is eye-clean?

Truthfully, the only way you can be 100% certain is by physically looking at the stone with your own eyes. I realise in a world where more and more diamonds are being purchased online that this seems moot. However, a simple place to start would be by asking the vendor – whether in store or online – if the SI1 Clarity grade diamond you are considering is in fact 100% eye-clean? They should be able to verify this for you.

But surely there must be another way?

Well, some of the key factors that our gemologist looks out for to get a strong indicator are:

  • Download the PDF of the GIA Certificate from and take a close look at the diamond plotting chart (i.e. the location of the various inclusions on the diagram of the diamond).
  • What type of inclusions or clarity characteristics does the diamond have? Our gemologist loves to look for SI1 clarity diamonds that have any of the following - twinning wisps, clouds, needles, pinpoints, and crystals or feathers that are not in the diamond's table (i.e the centre of the diamond). These are good indicators that the SI1 clarity grade diamond is in your favour!
  • Pay attention to the location, number of, and size of 'crystals.' If they are quite evident in the diamond's table, chances are the SI1 diamond is not eye-clean.
  • Every now and again even our gemologist has to ask himself - does the price seem a little too good to be true? Chances are, if it is - it's not going to be eye-clean. An example that was shared was when the location of a particular crystal seemed safe, but when the actual stone was viewed, the crystal reflected itself in a number of facets - making that one crystal seem like there were seven of them. Such diamonds are priced lower, and hence can sometimes come across as a great bargain - unfortunately, it's the exact opposite!

Rest assured that the perfect SI1 Clarity Grade is out there. Macro-lens photographic capabilities have made the process of finding such diamonds easier, making us less reliant on the diamond plotting. It may take a little more time, but more and more diamonds come on to the market everyday.

Our Diamond Concierge Service is completely free. There's no obligation to purchase from us. We're here to shine some light - and will always do so unbiasedly. Let us help you find your perfect diamond.