4 Best Places to Buy SI Diamonds in 2023 (Top Picks for You)

Last Updated on June 8, 2023 by Juli "Jewels" Church

Looking for the best place to buy SI Diamonds online?

Perfect! In this LearningJewelry.com guide, you’ll learn:

  • What Are SI Diamonds?
  • Red Flags When Buying SI Diamonds
  • Are SI Diamonds Worth the Price Tag?
  • And much more!
Best Places to Buy SI Diamonds

Below is a quick list of all my top picks. Keep scrolling to learn more about my best buying tips and tricks as well as a comprehensive FAQ section. 

Top Places To Buy SI Diamonds Online

  1. James Allen (My Top Pick)
  2. Blue Nile

What Are SI Diamonds?

Once diamonds were able to really be cut to showcase their brilliance, the industry realized they needed a system to distinguish high-quality diamonds from those of lesser quality. 

The Gemological Institute of America (GIA) was created to enforce this system. Since 1931, the GIA has been the world's resource for all things jewelry and gemology. 

The system they created is known as the 4Cs and it's a system that every retail diamond jewelry store in the world follows.

The 4Cs of diamond quality are Cut, Color, Clarity, and Carat.

Check out the full diamond clarity scale below: 

SI diamonds clarity

SI diamonds are the second from the bottom tier of the Clarity scale. It consists of two level, SI1 and SI2.

SI clarity stands for 'Slightly Included.' That means you may be able to see slight inclusions with the naked eye. You'll definitely see them under 10x magnification. However, it's possible to get an eye-clean SI diamond, and I'll tell you how to do so a little later. 

1. James Allen

James Allen loose diamonds

If you're looking for a place with a wide selection of SI diamonds, James Allen should be your number one. And here's why. 

All loose diamonds at James Allen are certified. They have diamonds certified by the GIA, AGS, or IGI. Remember that you should only buy diamonds that have a certification from the GIA or AGS.  

When you buy a diamond from James Allen, or even just try to price compare with brick and mortar stores, it becomes apparent how much you don't need a flawless diamond to pick a great one.

Corporate jewelry stores will sell you an included diamond for much more than James Allen would. They'll tell you that it's natural and there's nothing they can do. They'll encourage you to go for more expensive clarity grades like a VVS1 or VVS2 diamond if you don't want visible inclusions. 

James Allen offers complete transparency. They let you choose from over 3,400 1-carat SI diamonds with varying diamond grades. 

You can use their interactive 360˚ viewing technology that allows you to handpick your diamond for your own ring. By doing it this way, you're able to find a nicer, eye-clean diamond for cheaper.

On average, a 1 carat SI2 clarity with H color grade diamond at JA will run you around $2,600 on the low end and $4,500 on the high end. 

In addition to competitively priced diamonds, James Allen offers special education. You can actually work with a gemologist during a diamond inspection. They'll actually go over that specific diamond with you, including its report. Any questions you have, they'll answer. 

And if all this control wasn't enough, they also give a free warranty with all of their engagement rings and fine jewelry. The warranty will cover all the routine maintenance your ring will need as well as one free resizing within the first year.


  • 3,400 SI diamonds
  • Offers Lab created diamonds and fancy colored diamonds 
  • Lifetime Warranty


  • Offers IGI certified diamonds
  • Can't return special orders
  • 2. Blue Nile

    Blue Nile diamonds

    Blue Nile has a large selection of SI1 and SI2 diamonds. While they don't all have 360˚ viewing, there are plenty diamonds that do. You should be able to find a beautiful high quality diamond of varying grades and diamond shapes. Over 1,800 of their 2,500 SI diamonds have 360˚ viewing, so no worries there. 

    Blue Nile's loose diamonds are all certified by the GIA, so you can be sure they've been looked over by the world's best diamond experts. A 1 carat ideal cut SI1 diamond with H color from Blue Nile may run you around $4,000-$5,000 in the low to mid range. They are slightly more expensive than close competitor James Allen. 

    Blue Nile offers all their customers free returns within 30 days, but remember that special orders don't count. They also only have a manufacturer's warranty, which means they won't cover services like rhodium plating, prong retipping or stone tightening. But they do give you a free ring resizing if you need it. 


    • 1,800 SI diamonds
    • All diamonds are GIA-certified 
    • Good standing customer reputation 


    • 360˚ viewing on some diamonds, not all
    • No warranty

    Are SI Diamonds Expensive or Cheap?

    I diamonds are the lowest tier on the clarity scale, so they're going to be the least expensive clarity available for diamonds. However, diamond prices are assessed by many different factors, not just the 4Cs. Fluorescence, proportions, and diamond shapes can all play a part in diamond price. 

    The price of an I diamond depends greatly on where you buy diamonds from. If you're set on buying an I clarity diamond, I'd encourage you to buy from an online diamond store like James Allen or Blue Nile. 

    But most people shop in brick-and-mortar jewelry stores like Jared or Zales. The truth is, these mega corporate jewelry stores are overcharging I diamonds. I went to Zales.com and built a simple solitaire setting with a 1 carat I1 and I color engagement ring. It is $6,500. 


    Sample solitaire setting selection at Zales.com. 

    Now, I've taken the the same diamond grades and created a similar solitaire cathedral diamond ring from James Allen.

    Here's the price of this ring: 

    James Allen engagement ring

    Sample solitaire engagement ring at James Allen.

    Of course, there are differences between the two. James Allen's ring is set lower, which is actually better because high set rings are more likely to get damaged quicker. They just end up bumping things more. 

    But the slight differences shouldn't account for a $2,800-difference, should it?

    I mean, for the price of an I diamond ring at Zales, you could buy some matching solitaire stud earrings to go with your engagement ring and still save money on a warranty.

    If you're buying this I diamond engagement ring, you can save 57% shopping online with James Allen instead of Zales.

    Of course, you'll choose your own diamond so it could be more expensive or less expensive. But you are in control of your product! 

    What Should You Look for When Buying SI Diamonds Online?

    We know that there are other factors that contribute to the quality of a nice diamond. Here are some things that are worth knowing when picking out an SI diamond online. 

    The quality of the diamond will not just be judged by SI clarity alone. We still have three other Cs that contribute to diamond quality, and that's excluding other small factors like diamond fluorescence and proportions of diamond shapes other than round cut diamonds.

    Carat Weight 

    The carat weight of the I diamond you're choosing will have a big impact on both quality and cost. You can buy a gorgeous 1-carat ideal cut diamond with J color and SI1 clarity. But take those same diamond grades and choose a 2-carat marquise instead, and you'll actually be stuck with a lower-quality diamond and a less attractive one at that. 

    Bigger is not always better in diamonds. The larger carat weight you choose, the higher your other diamond grades have to be in order for the diamond to still be pretty. Ideal cut diamonds may be the exception to this guideline. 

    This is because ideal cut diamonds have been cut so well that the brilliance displayed distracts from lower color grades. It also hides inclusions better in its sparkle. With your SI1 diamond it won't be too hard to find any eye clean one, but it can be even more difficult in a 2 carat. 

    It's much easier for diamond cutters to cut a smaller diamond than a large one. This is one reason why you'll notice that a 2-carat diamond is not double the cost of a 1 carat.

    Cut and Shape

    The other grades have to be up to par. Additionally, a marquise-shaped diamond is more likely to chip because of its points. They are also susceptible to the bowtie effect. The bowtie effect happens on both marquise and pear diamonds.

    Princess cut diamonds also can chip more, even though they are brilliant cut. 

    Brilliant cut diamonds are a great diamond shape for those whose center diamond may have darker inclusions. Your brilliant cut shapes have tiny facets that make a diamond sparkle.

    Shapes like round cut, princess cut, ovals, marquise and cushion cut diamonds are all brilliant cut shapes. This pear cut diamond below is also a brilliant shape. 

    Read also: Should you buy a princess cut diamond?

    James Allen pear-shaped diamond

    Pear-shaped diamond at James Allen.

    Because it can be difficult to find an appealing step-cut diamond with I clarity, you should have better luck finding a nice SI clarity diamond. Step cut diamonds are your emerald cuts and Asscher cut diamonds.

    Asscher cut diamond at James Allen

    Asscher cut diamond at James Allen.

    Diamond Visibility

    Because SI diamonds aren't considered eye-clean, you should only purchase SI diamonds from an online retailer that has some kind of viewing technology, preferably a 360-degree viewer.

    James Allen, Blue Nile, and Whiteflash all offer 360-degree viewing. However, it's worth noting that James Allen is the only one with this technology on every single loose diamond in their inventory. 

    James Allen and Blue Nile both allow you to toggle the diamond back and forth, catching the light. By seeing your diamond this way, you'll be able to catch any dark or obvious natural inclusions your SI diamond will have. 

    Diamond inclusions are completely natural, and they're often an indicator that you in fact, are in possession of a real diamond. There are many diamond simulants, or stones that are similar in appearance to diamond, but have very different chemical and physical properties. 

    SI diamonds are the last tier before you head into the eye-clean clarity grades. If the diamond is eye-clean, very slight inclusions may be seen under 10x magnification.

    Not all inclusions are the same. You'll find the darker, more obvious inclusions in lower clarity grades. 

    Selecting Your Own Diamond

    Keep in mind that by selecting your diamond personally, you can ensure you have the best looking diamond for your money.

    SI2 diamonds are more likely to be harder to find without any obvious diamond characteristics, while you should have a bit easier time with SI1 diamonds. 

    Many physical retail stores don't allow you to choose your own diamond. Recently, stores like Kay Jewelers and Jared have added loose diamonds to their websites, but not in their stores. They don't have near as much stock either, and they aren't GIA or AGS certified. 

    By picking your own diamond, you can ensure that you choose a diamond that maybe has some inclusions, but they're found near where a prong might go or in very small clouded areas.

    Below, white inclusions like the SI2 diamond on the right is much more preferable to the one on the left, don't you think? The two are both H color, SI2 clarity, excellent cut, 1.01 carat diamonds with an IGI certificate. Can you spot the difference? 

    SI2 clarity diamond
    SI2 clarity diamond

    Diamond Certification

    You'd be surprised how many people who walk into a famous online retailer like Kay or Zales don't know anything about diamond certification. Which is heartbreaking, really, since it's one of the most important factors in your quest for SI diamonds online. 

    The reason why diamond certification is so important for the diamond buyer in general is because it basically ensures that you have purchased exactly what you have paid for. Let me elaborate. 

    There are many different diamond labs you can receive certification from. Some of the most popular labs include the GIA, American Gem Society (AGS), International Gemological Institute (IGI), European Gemological Laboratory (EGL), and Gemological Science International (GSI). 

    Gemex Reports are also grouped into diamond certifications, but they are simply light performance reports. Similarly, a diamond with a serial number inscribed on the girdle is not a certification. That just makes sure that if your ring is stolen, they'll know if someone pawned it. Very useful tool, and you can actually have it done with any diamond at the GIA. 

    We only recommend buying SI diamonds (or any diamond) with grading reports from the GIA or the AGS. These are the top two trusted diamond labs in the world.

    It should also be noted that the GIA doesn't technically have ideal cut diamonds, but Excellent Cut is exactly the same. You'll find the term ideal on your report from the AGS. 

    Read also: Diamond grading labs you should avoid

    The problem with the other labs mentioned and even some I didn't mention, is that their diamond grade restrictions are a bit looser than the two aforementioned.

    You could buy an IGI-certified SI2 diamond, and then have it graded by the GIA to find out they graded it as I1 clarity. This is a big deal since the price difference between an I1 and an SI2 are at least a few hundred dollars.

    Furthermore, if you were ever trying to sell your diamond, most jewelers only accept diamond with certifications from either the GIA or AGS. So, don't settle for less than GIA or AGS.

    GIA report

    Sample diamond grading report from www.gia.edu

    Warranties and Returns

    Another very important thing to remember that many online diamond buyers forget to consider is a warranty and return policy.

    If you've dropped a few grand on a fantastic SI diamond and ring setting, you probably don't want to think about paying for a warranty. After all, if you paid this much, it should last forever, right?


    The truth is, jewelry is made of natural materials that don't last forever. Most online diamond engagement rings are set in either white gold, yellow gold, or rose gold. Some choose platinum, which is much stronger than gold, but comes with some weight to it.

    Pure gold (24 karat) is very soft, which is why you won't find engagement ring settings with it. Some countries carry higher karats in gold jewelry, but those are very delicate. 

    Delicate gold is not the best for a ring you're planning on wearing everyday for years and years. So, it has to be mixed with other metals to give it more durability. 10k, 14K,  and 18K gold lets you know how many of the 24 parts are pure gold. The higher the karat, the softer it is. 

    Most jewelers sell engagement and wedding rings in 14K and 18K. Both of these are good for everyday wear, but 18K will probably wear down a little faster.

    You see, we don't realize how hard we are on our hands throughout the day, even if you're not doing manual labor. You brush your hands against all kinds of surfaces, be it the desk, coffee cup, while cooking, etc.

    Gold will get damaged with little scratches and nicks. White gold, the most popular color gold for engagement rings, has to be rhodium plated. It starts to yellow due to natural oils in the skin. By replating it, the silvery color returns.

    Most white gold rings have to be replated once a year. But for some, their skin's natural oils cause the silver to fade even quicker. 

    Read also: Where to buy white gold jewelry?

    This is why you should be buying diamonds from a diamond retailer that offers a lifetime warranty. But don't just stop there because there are different kinds of lifetime warranties.

    Many retailers like Blue Nile or Leibish & Co. offer what's called a manufacturer's warranty. These only cover design flaws or repetitive issues. They don't cover rhodium, stone tightening, or prong retipping. Still, they're advertised as a lifetime warranty.

    Make sure you read the terms of the warranty before buying. Some brands exclude designer rings in their warranties. The other thing you want to make sure of is the place where you are buying diamonds 

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