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Summary
If you’re trying to decide on a clarity grade for your diamond, SI1 might be your best option. These diamonds usually appear flawless to the eye and sell for less than VS diamonds. Learn more about SI1 clarity diamonds and how to choose the right one for your engagement ring.
Reading time: 8 min

SI1 clarity diamonds, like this center stone, can seem flawless to the eye. © CustomMade. Used with permission.

Anyone buying a diamond online needs high-quality, magnified videos of the stone to judge its quality. We recommend using James Allen or Blue Nile for just this reason. Their closeup videos really let you see the clarity flaws and assess the cut quality, letting you find the best eye-clean diamond.

If you’d prefer to go custom, check out CustomMade. Their team of experts can help you decide on a clarity grade and put that perfect diamond in a ring that’s 100% you.

What Does SI1 Clarity Mean?

Diamonds receive grades on each of the Four Cs from a gemological laboratory. Their clarity grades can range from “Flawless” (F) to “Included” (I). “Slightly Included” (SI) is on the lower end of the range and has two subdivisions. SI1 has the fewest and smallest inclusions, while SI2 has more and larger inclusions.

This doesn’t mean that SI clarity diamonds are a poor choice. In fact, most SI1 clarity diamonds will look just as good as a higher clarity diamond.

Although both these rings from James Allen feature eye-clean diamonds, they have very different clarity grades. The first is a VVS2 and the second is an SI1.

Eye Clean or Visibly Flawed?

The key to choosing a diamond clarity grade is making sure you’ll have an eye-clean stone. In other words, none of the flaws in the diamond should be visible to the naked eye at a normal viewing distance.

So, are SI1 diamonds visibly flawed? Not necessarily. There are so many clarity grades above SI1 because gem labs use microscopes to see tiny inclusions and imperfections. Their presence or absence factors into clarity grades. However, unless you have superhuman vision, an SI1 clarity grade can still be a great option for a ring.

The SI1, oval-cut diamond in this James Allen solitaire ring has a flaw that reflects across its facets, but it’s hard to see this effect after the stone is set in the ring.

Diamond Clarity and Price

Clarity grades can have a significant impact on a diamond’s price. We always recommend opting for the lowest clarity diamond that will still look good in a ring. That way, you can put the money toward a larger carat diamond rather than paying for a “better” clarity grade, when you’ll never be able to see the difference.

Take a look at these 1.01-ct, H color diamonds. Both are eye-clean, but one has VS2 clarity and sells for $5,800, while the other has SI1 clarity and sells for $4,750. Can you guess which is which? Compare them side-by-side at James Allen.

Buying an SI1 Clarity Diamond

If you choose an SI1 clarity diamond, it’s important to understand what this clarity grade might reveal about your diamond. Different clarity features can have different effects on a diamond’s beauty as well as durability. They may influence your choice of diamond shape, too.

Types of Clarity Features

Several different types of clarity features might occur in a diamond. Some are mineral inclusions, while others are imperfections on the surface or in the diamond’s crystal structure.

Most flaws in SI1 diamonds will be crystal inclusions, pinpricks, or cloudy formations. Twinning wisps and cracks or “feathers” also contribute to the diamond’s clarity grade. Each of these types of clarity features can be large or small and can occur in any color.

When it comes to clarity grading, smaller and lighter-colored flaws don’t have as much impact as large or dark ones.

Both of these SI1, princess-cut diamonds have big flaws right at their centers. However, one has a light-colored flaw that would be hard to notice, while the other has a readily noticeable dark flaw. Compare these James Allen diamonds side-by-side.

Location of Clarity Features

Whether or not a diamond is eye-clean depends greatly on the location of its flaws. For example, flaws near the middle of the diamond are readily noticeable, while those toward the edges may be less noticeable. In fact, jewelers may be able to hide outlying inclusions under prongs.

SI1 clarity cushion-cut diamond

This SI1, cushion-cut diamond has a flaw near the corner to the right. This is much less noticeable than a centered flaw. Take a look at the video on the James Allen site.

If you can’t see the flaws in a diamond under a magnified view, take a look at the clarity chart or plot on the diamond’s grading report. This will show you the location and types of clarity features in the diamond. Keep in mind that the plot view might be rotated from what you see in a magnified video.

Durability Concerns

Just because diamonds are the hardest minerals doesn’t mean they can’t chip or break. In certain cases, diamonds with low clarity grades might be more susceptible to chips and fractures. In terms of durability, large flaws raise the most concern. They can create vulnerable spots where the diamond is more likely to break.

Any clarity feature at the diamond’s surface is also a cause for concern. Since determining whether these features reach the surface can be difficult, consult a gemologist about a diamond’s clarity features before you buy. If you’re buying online, both James Allen and Blue Nile have experts on call to answer your questions.

Diamond Shape

The diamond shape you prefer should factor heavily on the clarity grade you choose. For most shapes, an SI1 clarity diamond will be an excellent choice. However, emerald and asscher-cut diamonds make clarity features much more visible. We recommend choosing a VS clarity diamond for these shapes.

emerald-cut SI1 clarity diamond

Emerald-cut diamonds, like this one, act like a series of mirrors reflecting flaws throughout the stone. See the video of this diamond on the James Allen site.

In addition, pay special attention to the location of clarity features in any shape with a sharp point. Flaws in the corners of princess, pear, marquise, and heart shapes can make the diamond vulnerable to breaking. That’s because the prongs placed on these spots put pressure on the diamond.

Zooming Out

To evaluate clarity, you absolutely must have a magnified view of the diamond. This will allow you to see the clarity features clearly. However, these magnified views also make it difficult to tell if a diamond will be eye-clean when set in a ring.

magnification of flawed diamond

With a magnified view, the flaw in this diamond is large and easy to see. When you zoom out, it’s more difficult to spot. This is a good diamond for practicing clarity evaluation. Try it for yourself on the James Allen site.

So, when you’re shopping online, remember to zoom out when you’re viewing diamond images and videos. Keep the locations of the flaws in mind, too. If you can still see them while the diamond appears on the screen the same size as it would on your finger (for a one-carat round diamond, about 6.5 mm or approximately a quarter-inch in diameter), the stone won’t be eye clean. On the other hand, if the flaw disappears in the diamond’s sparkle, you might have a keeper. Nevertheless, consult with an expert before you buy. A professional may be able to see a flaw more easily in person than on a video.

Considering a VS2 or SI2?

If you have concerns about buying a flawed SI1 diamond, there’s nothing wrong with moving up to a VS2 clarity grade. Moving up a grade will alleviate your worries about buying a visibly flawed diamond. While a VS2 stone will cost more, shopping around isn’t everyone’s style.

That said, if you’re the type to brag about saving on a diamond (or if you’re simply on a tight budget), you could consider buying an SI2 clarity diamond. There are plenty of eye-clean SI2 clarity diamonds, though finding them might prove difficult. On the other hand, if you’re OK with a tiny flaw that’s tough to see without pointing it out, an SI2 might be the best option for you.

si2 diamond engagement ring

The big flaw in this SI2 clarity diamond is hardly noticeable to the unaided eye. Take a look at this James Allen ring.

Questions to Ask a Gemologist

When you’re buying an SI clarity diamond, you’ll want some assurance that the stone is a good choice. Both James Allen and Blue Nile let you chat with diamond experts. If you’re buying a stone in person, most brick-and-mortar jewelry stores have a gemologist on staff. Here’s what you should ask before making your final decision:

  • Is this diamond eye-clean?
  • Are any of the inclusions near the surface?
  • Do any inclusions make the diamond more likely to chip or break?
  • Is it possible to hide the inclusions under a prong? Will this make the diamond more likely to chip?

Learn More About Diamond Clarity

If you’d like to learn more about diamond clarity, check out our complete consumer’s guide.

Of course, if you’re buying from James Allen or Blue Nile, you can chat with their diamond experts before you buy. They can address any concerns you have about the diamond’s clarity.

Working with a custom jeweler like CustomMade is another great way to ensure that your diamond will suit you perfectly. They can help you create a stunning ring with a great, eye-clean diamond.