One of the most sought-after gemstones in the world, diamonds are one of the hardest substances known to man. Diamonds form from carbon under high pressure and temperature.

Why are diamonds so popular?

Fun backstory: diamonds weren't commonly used in engagement rings until 1947, when the British mining company De Beers featured them in an advertising campaign! The rest, as they say, is history. Diamonds now represent financial success, long-term commitment, and status.

What are the "4Cs" when shopping for a diamond?

Cut, carat, color, clarity. Cut is the only human "influence" on a gemstone: round, princess, cushion, marquise and oval are some of the more common shapes given to diamonds. Carat represents the weight of the diamond, with 1 carat equal to 200 milligrams. Color evaluates the stone using letters of the alphabet; the closer to "A", the whiter the stone, though most people find stones in the G-H rating to still be icy-white in appearance. Clarity is a little more difficult for the average consumer to see, especially without magnification: the categories measure inclusions, or irregularities that happen during the formation of the diamonds but are hard to see without magnification, as well as blemishes like scratches or chips.

What's the difference between natural and lab-created diamonds?

The names say it all: natural diamonds come from the earth, while lab-created or synthetic diamonds come from scientists! But, other than their origins, these two types of diamonds are exactly the same chemically and optically: even expert gemologists have a hard time telling them apart without using a jeweler's loupe! And, as you might imagine, synthetic diamonds are usually much more affordable.

What are GIA, AGS, EGL and IGI?

These acronyms all refer to gemological societies and institutes with diamond grading scales used throughout the industry: Gemological Institute of America, American Gemological Society, European Gemological Laboratory, and International Gemological Institute. Generally speaking, GIA and AGS are seen as the most accurate and scientific, so if you're buying a higher-priced stone you may want to ensure that it's been graded by one (or both!) of those two systems.

Why would I buy a loose diamond instead of an already-made engagement ring or other piece of jewelry?

If you're looking for a one-of-a-kind piece, you're not going to find it by buying the first pretty ring or solitaires you see at your local jewelry store. Many customers want something with a story that can be handed down as an heirloom: the shape of the stone chosen to match her eyes, the setting selected to complement his personality, and so on. Buying loose diamonds is the first step in a truly unique piece of jewelry.

Are diamonds a good investment?

While you'll find no shortage of companies wanting to sell you diamonds as an investment, most experts say that the average consumer isn't likely to profit from them. Unless you're buying extremely large diamonds (e.g. 20 carats or more) or ones with a noteworthy history (like being owned by a celebrity), you may have a hard time selling the diamonds you buy for more than you paid. If you're planning on spending a significant amount of money for a diamond, do it because you appreciate the beauty or want to own (or give) something precious - but save your investments for more reliable means of generating profits!

Is it safe to buy loose diamonds online?

Absolutely. Of course, you shouldn't buy a diamond from an online retailer without doing your research: choose a business with a well-established history, preferably with a high rating from the BBB, and be sure that the diamond you buy has been rated and certified by one of the independent institutes or laboratories mentioned above. You can rest assured that the diamond retailer will take every measure to get your stone delivered safely, including tracking and insurance.

James Allen vs 25 Karats for January 2026

Item: James Allen vs 25 Karats
Rating: 3.5
Author: Top Consumer Reviews

Sunday, January 18th We evaluate products and services based on unbiased research. Top Consumer Reviews may earn money when you click on a link. Learn more about our process.

2026 Diamond Store Reviews

Here you can see how James Allen and 25 Karats match up head-to-head in a battle for the Best Diamond Stores in 2026.

James Allen

Prices from $200 to $5 million per loose diamond
316,758 diamonds in stock
Includes preset diamonds

James Allen is a well-known online jeweler that launched in 2006 and now offers over 316,000 loose diamonds along with a wide selection of engagement rings and fine jewelry. The diamond store website makes shopping easy with 360-degree views of each diamond, filters for shape, cut, clarity, and carat, and prices that include some budget-friendly options. James Allen also provides extras like a lifetime warranty, free resizing for a year, and 30-day returns, although its customer reviews are slightly mixed compared to some competitors.

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25 Karats

Prices from $69 to $181,713 per loose diamond
8,851 diamonds in stock
Includes custom designs

25 Karats is a New York City jeweler that has been offering wedding rings and fine diamonds since 2008. The diamond store carries over 8,800 conflict-free diamonds in a wide variety of cuts, colors, and clarity levels, along with custom jewelry backed by a lifetime warranty. With strong customer reviews, a 60-day return policy, and an "A+" BBB rating, 25 Karats stands out as a trusted choice for engagement rings and other special pieces that spotlight diamonds.

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Few things on earth rival the beauty of a diamond. Its allure begins deep underground, where intense heat and pressure forge the crystal, continues through the hard work of mining, and culminates in precise faceting that unlocks its brilliance. Each stone carries a journey - from mantle to mine to bench - that sets it apart from other gemstones. These days, people also weigh origin and ethics, which adds another layer to the decision. Choosing a diamond isn't just a purchase; it's a meaningful moment you'll remember.

Whether you're hunting for the perfect stone for an engagement ring - and congrats on the big ask - or you're after a piece that truly pops, a diamond necklace or a pair of earrings can turn heads like nothing else. Whatever you choose, picking a jeweler you trust is nonnegotiable. Take time to compare shops, ask for certifications like GIA, and look for clear policies so you know exactly what you're getting.

Choosing the right diamond store feels a lot like picking the perfect piece of jewelry - it should suit you, not just anyone. You want a place that's on your side, with a deep selection and genuinely attentive service. Whether you're after a round, oval, cushion, emerald, or princess cut, the shop you choose should offer every sparkle your heart's set on. And as you compare options, look for transparent grading details and knowledgeable staff who guide you without pressure, so you leave feeling confident and excited.

Here's the upside: modern diamond retailers let you shop entirely online, so you're not stuck with whatever your local stores happen to carry. Many still keep nearby showrooms if you'd rather browse or inspect pieces in person. The experience goes a step further - high-res videos, virtual consultations, and clear grading reports make comparing stones simple before you ever decide to buy. All told, it's easier than ever to order diamonds or other fine jewelry without leaving home.

Buying diamonds online now feels almost like stepping into a boutique. High-resolution 3D spins and full videos let you examine rings, necklaces, and loose stones from every angle, and you're not limited to whatever a single store has in its case - you can browse the entire inventory and hunt for truly exclusive gems. On top of that, price-match policies, wholesale-level pricing, and lifetime guarantees raise the value proposition, promising a best-in-class shopping experience that makes gifting and milestone moments even more memorable. Many retailers even offer virtual appointments with gemologists, so you can get expert guidance without leaving home. In short, the digital showroom puts more choice, transparency, and confidence at your fingertips.

If you're searching for that perfect fit and need the top diamond store out there to meet your needs, we get it. When you're going for diamonds (no matter the karat or cut), you want the best service to match. To help you find the best fit, we've put together some factors to help you make your final decision:

Inventory. When you're picking your preferred diamond store, you'll want to look at the inventory. How many cuts of diamonds are offered? Can you get different colors or unique styles that aren't found at other stores? Make sure that the competitive selection includes everything you want (and more), so you can count on the one-stop shop to help you with this and all your future diamond needs.
Browsing tools. How easy does your chosen diamond store make it to browse? Is it easy to filter the selection of diamonds? Can you preview the diamonds with 360-degree views or 3D images to make sure you get a good look at your diamond or jewelry piece long before it arrives at your home? Your chosen diamond store should include all the browsing bells and whistles.
Cost. Buying diamonds can be costly, so pick a diamond store that's within your budget. Many of the top diamond retailers will offer wholesale prices (especially if there are no overhead costs associated with a brick-and-mortar location). You can also search for seasonal deals and pieces that are on sale to keep the final cost a little lower. But, if you're looking to splurge on your diamonds (this note is for you, fellas), your chosen diamond store needs to have those high-end, showstopping stones that stand out from the pack.
Reviews. Choosing a diamond store can be a bit stressful. When you're spending that much on something so special, you want to feel confident that you're getting the best service. Check out your chosen diamond retailer on trusted third-party review sites with verified shopper feedback. This way, you can see how other buyers just like you felt about diamond quality, customer service, and other important parts of the diamond buying process. Particularly helpful review sites include Trustpilot, Sitejabber, and (of course) the Better Business Bureau.

Whether you're getting ready for the most important moment of your life (wedding bells, anyone?) or looking to celebrate an anniversary, or just buy something beautiful for someone you love, diamonds are still the best way to treat someone extra special. To help you pick the best place to score beautiful diamonds, Top Consumer Reviews has researched and ranked the best options for diamond stores on the market today. This way, you can focus on finding the perfect cut and setting, and celebrate the joy of a special sparkly with someone you love. Congrats!

What are the benefits of buying loose diamonds?

When many people think about diamonds, buying diamond jewelry from a local store immediately comes to mind. However, buying loose diamonds is an option as well. At first glance, it may seem easier to simply walk into a jewelry store and buy a diamond ring or necklace, but the reality is that there are several exciting benefits associated with buying loose diamonds. In fact, with a closer look at the benefits of buying loose diamonds, you may decide that this is the best option for you. What can you expect when you buy loose diamonds?

Online Research

When people initially start shopping for a diamond, they focus on carat weight. While this is an important factor to consider, there are other factors that impact a diamond's true value. In addition to the carat weight, the stone's cut, clarity, and color play a role. These are referred to as the 4Cs of diamonds, and they are reviewed during the diamond certification process. One of the easiest ways to buy loose diamonds is online, and you can conveniently complete online research on all of these important factors before you make your purchase. Some diamonds used in preset jewelry are not certified, so you may not be able to determine the true value of that jewelry.

Not all loose diamonds are certified, but some sources exclusively sell certified diamonds. These are diamonds have been analyzed by a reputable lab, such as GIA, EGL, AGS or a few others. Through the certification process, a diamond's characteristics are mapped. This includes its flaws, dimensions and other key features. In fact, the certification process covers the 4Cs of diamonds. The lab certification report for a specific certified diamond is usually readily available for you to view online when you buy loose diamonds, and this makes it easy for you to understand fully what you are buying before you finalize your purchase. Many jewelry retailers, however, may not provide the certification documents to you unless you specifically request them.

Be aware, however, that you should not assume that the gemstone that you purchase online is the same diamond that you will receive in the mail. You should always obtain an appraisal from a certified professional as soon as you receive your loose diamonds. This holds true if you buy a diamond in a setting. The good news is that it is much easier for an appraiser to inspect and appraise loose diamonds versus those that are in a setting.

Comparison Shopping

Are you concerned about overpaying for diamonds or diamond jewelry? Because of the wealth of online information that is available on certified diamonds for sale, it is easy to comparison shop for the best value within your price range regardless of whether you buy a loose stone or a diamond in a setting.

However, when you purchase a diamond in a setting, there may be a question about how the setting's design and materials impact the total cost of the jewelry. When you purchase a loose diamond that is certified, on the other hand, you will know exactly how much that specific diamond is worth. This gives you some control over both value and cost. Whether you intend to hold loose gemstones or to place a diamond in a setting at a later date, the ability to easily comparison shop will help you to avoid overpaying.

A Financial Investment

The value of both loose diamonds and diamond jewelry will fluctuate over time, but you can expect them to share an upward trajectory over a long period of time. You may assume that loose diamonds will hold their value just as well as diamond jewelry would, but this is not always the case. In fact, loose diamonds generally hold their value better than diamonds that are set in earrings, necklaces, earrings and other settings. This is particularly true when you purchase certified loose diamonds.

Why is this the case? Some of the diamonds used in earrings, necklaces and other pieces have not been certified, so you cannot truly know the value of the gemstones when you buy these prepared pieces. This means that you also cannot truly determine the value of the jewelry, and you risk the possibility of paying more than the item is actually worth. When you buy a certified loose diamond, on the other hand, you will have a record of its value before it is placed in a setting. You will be less likely to overpay for that piece of jewelry, and the value of that jewelry will be partially secured by the diamond certification paperwork.

Keep in mind that many people purchase loose diamonds to hold securely for a period of time. For example, they may store diamonds in a bank's security deposit box or in a locked safe in their own home. The value of diamonds has maintained an upward path over the years, so this could be a smart way for an investor to diversify his or her portfolio.

Access to a Large Selection

Generally, when you shop for diamond jewelry at a local store, you are purchasing the stone and the setting together. You do not usually have the option to change out the diamond. However, the ability to select the specific diamond for your setting gives you greater control over the quality of the finished piece as well as its cost and value. More than that, with the ability to mix and match diamonds and settings, you have access to a greater overall range of possibilities.

Are you wondering how significant this benefit is? A single diamond wholesaler may offer hundreds or even thousands of certified loose diamonds at any given time. With multiple reputable wholesalers available for you to shop with, you will have a huge selection to choose from when you shop for loose diamonds. Some online wholesalers offer a convenient search function so that you can easily narrow down the options specifically to those that meet your requirements for cost and price.

Your Choice of Settings

While many people choose to keep loose diamonds as a financial investment, others shop for a loose diamond with a more specific purpose in mind. For example, you may want to select the exact diamond that will be placed in a custom-made engagement ring or necklace. When you buy a loose diamond for this purpose, the possibilities are endless. A private jeweler may have some predesigned settings for you to choose from, and your selection of a specific diamond for that setting ensures that the jewelry is tailored to your budget and expectations.

Another exciting option is to work with a private jeweler to create a one-of-a-kind piece. Everything from the jewelry's metal and size to its style will be created to your exact specifications. In comparison, if you choose to buy a diamond that is already in a setting, you are truly limited to the possibilities available from that store at the time of your visit.

Diamonds are often used in jewelry that has special meaning, such as a wedding ring, an engagement ring, an anniversary ring and more. These are important pieces that you understandably want to be perfect for the individual and for the occasion. With this in mind, the ability to choose both the loose diamond and the setting is a true benefit.

Get to Know the Possibilities Today

Before you settle for diamond jewelry purchased from a retail store, you owe it to yourself to explore the exciting possibilities available to you with the purchase of loose diamonds. With gemstones available at a wide range of prices and qualities, you could potentially find exactly what you are looking for when you shop for a loose diamond today.

James Allen vs 25 Karats

2026 Diamond Store Reviews

James Allen

25 Karats

Diamond Store FAQ