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SI2 diamonds are popular for two reasons:

  • You can find beautiful, eye-clean diamonds within this clarity range.
  • Those diamonds will most likely represent very good value for money.

You can find diamonds like these quite easily online, as popular, experienced retailers such as Whiteflash, James Allen, and Blue Nile all stock them. And the benefit of online purchasing? You can take as long as you like to research, compare, and consider your choices. So when it comes to SI2 diamonds, what types of considerations should you be pondering? 

At the start of any successful diamond purchasing journey is the research stage. If you have your eyes set on an SI2 clarity diamond, or are simply curious about what they are, this helpful guide will tell you all you need to know. 

  • What Are SI2 Clarity Diamonds?
  • Examples of SI2 Diamonds
  • Are SI2 Diamonds Expensive?
  • How to Choose and SI2 Diamond
  • Should You Buy an SI2 Clarity Diamond?
  • Where to By SI2 Diamonds

What Are SI2 Clarity Diamonds?

SI2 clarity diamonds are those who have been inspected and given the SI2 clarity grading, sitting just below their counterpart, SI1. Clarity refers to the overall purity of a diamond. Alongside cut, it’s probably the most important quality that influences the light performance and brilliance of a diamond. 

Diamond clarity was originally created by the Gemological Institute of America (GIA), who divide clarity into eleven grades:

  • FL - Flawless
  • IF - Internally Flawless
  • VVS1 - Very Very Slightly Included 1
  • VVS2 - Very Very Slightly Included 2
  • VS1 - Very Slightly Included 1
  • VS2 - Very Slightly Included 2
  • SI1 - Slightly Included 1
  • SI2 - Slightly Included 2
  • I1 - Included 1
  • I2 - Included 2
  • I3 - Included 3
GIA Clarity Scale

The use of the word ‘included’ in these grades refers to the presence of ‘inclusions’, which are essentially internal or external blemishes in the diamonds themselves. These inclusions have the negative impact of slightly impeding diamond transparency and brilliance, as they affect a diamond’s ability to reflect and refract light. Some inclusions are so slight as to be impossible to see by the naked eye, whereas others are incredibly obvious. 

The simple rule is; the lower graded the diamond is, the more inclusions it has. Diamonds below and SI2 grade are unsuitable for high-quality jewelry, especially engagement rings. To determine clarity, diamond grading experts will inspect a stone and work to observe the type, size, number, relief, and location of any inclusion present. 

SI2 diamonds themselves are defined by the GIA as diamonds that have ‘inclusions noticeable to a skilled grader under 10x magnification’. Because it sits at the lower end of the Slightly Included grade, an SI2 diamond is more likely to contain noticeable inclusions.

Examples of SI2 Diamonds

Image courtesy Whiteflash

This 0.44 ct G SI2 Premium Select Round Cut Loose Diamond is a good example of a fine SI2 clarity diamond. As you can see, there are a number of inclusions present, but they are both small and scattered, with most of them present around the edge of the diamond. 

Inclusions present around the edge can actually be a boon for those looking for a less expensive diamond. While the inclusions necessarily preclude a lower price, these specific inclusions could potentially be covered by the setting used. 

Like other diamond clarity grades, SI2 can be subject to vastly different-looking diamonds.

Image courtesy James Allen

As you can see, this 1.01 ct G SI2 diamond from James Allen looks vastly different. The inclusions are much more apparent and therefore would be much harder to conceal. What this means is that if you do consider an SI2, you must inspect the diamond itself carefully. Not many SI2s will be eye-clean (where inclusions, if present, aren’t visible to the naked eye), but some may be close. In fact, only around 30% of SI2 diamonds are found to be eye-clean. Our overall rule is to always choose an eye-clean diamond, and if that means choosing a higher clarity grade, it’s usually worth the extra expense. 

It is definitely worth looking at a diamond’s inclusion plot graph to ascertain what type of inclusions are present, and where they are. Some inclusions may actually weaken the integrity of the diamond, which should be avoided at all costs. 

Are SI2 Diamonds Expensive?

SI2 diamonds are usually marketed as ‘bargains’ and are definitely less expensive than other diamond clarity grades. However, this doesn’t necessarily mean they are a bargain, especially if the inclusions ruin the diamond’s light performance. Price itself doesn’t necessarily correlate just to clarity grade, but is rather informed by the other Four Cs - Color, Carat, and Cut. 

For example, the diamonds above are priced at $750 and $3,430 respectively. Even though the former is evidently ‘cleaner’ than the latter, the difference in price is mainly caused by the latter being more than twice the size of the former. 

As you can see, price alone is not worth using as a benchmark for diamond purchasing. You need to consider price alongside many other facets that make up a diamond. 

How to Choose an SI2 Diamond

If you’re going to choose an SI2 diamond, there are a number of methods you can employ to ensure you get the best quality SI2 available.

Look for High-Res Images

In the search for the best quality online diamonds, high-res images, light performance images and videos are the best thing to look for. These visual documentations of the diamond will show you what the diamonds look like and potentially show you any inclusions. Videos are also fantastic at showing you how diamonds perform under light sources. 

We would recommend only purchasing an SI2 diamond if you’ve seen high-res imaging used on the site you’re on. 

Choose In-Stock Diamonds

Many online retailers operate with virtual inventories, where the diamonds they advertise aren’t actually available for them to view. Now, this isn’t necessarily a problem, but it means that if a customer is very discerning, they will be unable to view the diamond they’re considering, and visual verification is incredibly important. 

In-stock diamonds can be thoroughly vetted by in-house diamond experts, who can determine whether the advertised quality of the diamond is accurate. This is one of the reasons we particularly respect the work of Whiteflash, the majority of whose inventory is in-house. In-house diamonds can immediately be inspected upon the request of the interested party, who is able to benefit from an in-depth report about that diamond and its inclusions. When it comes to SI2 diamonds, this is a real advantage.

Documentation and Plot Graphs

Every diamond retailer worth their salt should include documentation to verify the quality and grading of a diamond. If they don’t, don’t buy from them. 

Documentation, such as diamond certification, will show you that the diamond has been properly vetted by independent experts from organizations such as the GIA or the American Gem Society (AGS). Inclusion plot graphs will be able to show you the location, number, and type of inclusions present in the diamond.

Remember the Four Cs

Again, we will reiterate that diamonds aren’t to be judged on their price alone. Developing a good knowledge of the four Cs—Clarity, Cut, Color, and Carat—will help you better determine the quality of a diamond and whether you are getting a good deal. 

You can find more information about the Four Cs in our diamond education section.

Should You Buy an SI2 Clarity Diamond?

We will always recommend purchasing a diamond that sits in the VS range and upwards. At higher grades such as these, you are practically guaranteed to find an eye-clean diamond that really packs a punch in terms of light performance. It may also be a lot quicker to find an eye-clean diamond to your liking at higher clarity grades, which is a real advantage for those working to a schedule. 

Ultimately, the decision to buy an SI2 is completely up to you. Any diamond search will be influenced by your taste, budget, and time. We recommend doing your research first, so that these three important currencies can be used to the best of their potential. 

Where To Buy SI2 Diamonds

Here at Diamond Expert, I often recommend three top sellers when it comes to high-quality diamonds; Whiteflash, James Allen, and Blue Nile. While they each have their respective strengths, these three diamond retailers lead the way in online diamond selling. Their diamonds are top-quality, their in-house team are experts, and their customer service is unmatched. 

To discover our full and detailed thoughts on these diamond retailers, visit our review section.