A Diamocycle Guide to Buying Used Diamonds

Table of Contents:

A Guide to Buying Used Diamonds 

What to Know Before Buying a Used Diamond



What are The 4 Cs?

What’s the Difference Between Natural and Man-made Diamonds?


How Do the 4Cs Affect Diamond Pricing?

What Else Determines a Diamond’s Price?

How Does the Diamond Supply Chain Work?

Are Diamonds a Strong Investment?

Tips for Buying Diamonds as an Investment  


Buying Used Diamonds at a Jewelry Store

Pawn Shops & Diamonds

Tips for Buying at a Pawn Shop

Used Diamonds at Fine Auction Houses

Can I Buy Diamonds on EBay & Other Non-Diamond Specific Online Marketplaces?

Critics’ Pick: Diamond Specific Online Marketplaces

Can I Buy Jewelry from My Friends?


Understand What’s Diamond Myth & Proper Procedures

Test Your Diamond

Differentiate Your Diamond from Other Stones


Buy from a Source You Trust

Keep Your Priorities in Mind

Understand Diamond Pricing

Consider Your Recipient’s Taste




Buying a diamond can be an intimidating process, especially when you’re looking to buy a used diamond or engagement ring. That said, equipped with the right knowledge, the process of buying a used ring or knowing used diamond prices can be straightforward and stress-free.

We’ve created the following guide to make buying a used diamond as easy as admiring one sparkle.


What are the Four C’s?

As always, we encourage all of our diamond buyers and sellers to have a strong working knowledge about the 4Cs of diamonds: color, cut, carat, and clarity. 

For those of you new to Diamocycle, here’s a quick overview of what makes a diamond a diamond:

Carat: A carat is a unit that measures a diamond’s weight. The higher a  diamond’s carat value, the heavier and more valuable the diamond. 1 carat is equal to .2 grams. 

Color: Diamonds are valued and rated by their color, which can vary across a  scale of D (void of color) to Z (yellow in tone). Colored diamonds prices depend on how clear the colors of the diamonds are. The clearer a diamond, the higher its rating and value. 

Cut: The way a diamond is cut determines its shape. Where there is no value scale based on cut, how a diamond is cut impacts its sparkle and how it can be used in a piece of jewelry. A perfect diamond cut is not probable, but the cut can be a big determination of price. Current trends and the execution of that style’s cut are usually the strongest factors that help determine value. 

Clarity: A diamond’s clarity is determined by the presence of inclusions (internal flaws) found on or in the stone. These inclusions can include blemishes, scratches, clouds, or other flaws, and each stone is rated on an industry-specific scale. The fewer the inclusions and marks, the clearer and higher value the stone. 

What is the Difference Between Natural and Man-Made Diamonds?

Diamonds can be made through a variety of processes both natural and synthetic. The word diamond refers to their molecular and crystalline structure, which can both be made through the workings of the natural world or in a lab. 

Here is our quick breakdown of the different types of diamonds and diamond substitutes. 

Natural Diamonds:. Natural diamonds are mined from the earth. The unique crystalline structure unique to diamonds is formed through billions of years of geologic processes. Given their uniqueness and the labor required to extract them, natural diamonds, both used and preowned, often fetch a commanding price. 

Synthetic Diamonds: Synthetic diamonds have the same crystalline structure and appearance as natural diamonds. The main difference, however, is that they are created in a laboratory. Given that their production is man-made rather than geologic, synthetic diamonds are more prevalent and priced as such. That said, synthetic diamonds and natural diamonds are visibly identical. The only way to tell the difference is through laboratory testing.

Please keep in mind that synthetic diamonds are real diamonds. Both natural and synthetic diamonds have the same properties and specifications. The sole difference is how they are created. You may wonder, are synthetic diamonds cheaper? Due to market forces, the price between the two items is considerable. That said, it would be incorrect to consider synthetic diamonds a “fake diamond.” As mentioned, the only way to know the difference is to submit your stone to a reputable diamond laboratory. 

Other Synthetic Stones: There are a variety of other stones that look like diamonds but have a crystalline structure of another type of stone.

Non-Diamond Synthetic Stones with a Natural Counterpart. Some synthetic stones have a natural counterpart, look like a diamond, and were created in a lab. Some examples of these stones are:

  • Synthetic Rutile

  • Colorless Synthetic Spinel

  • Colorless Synthetic Sapphire

Non-Diamond Synthetic Stones with No Natural Counterpart. There are also synthetic substances that have no natural counterpart. These synthetic substances look like a diamond, but have a different chemical composition. Some examples of such a stone are:

  • YAG (yttrium aluminum garnet)

  • GGG (gadolinium gallium garnet)

  • CZ (synthetic cubic zirconia)

  • Synthetic Moissanite

Whether you’re buying new or pre-owned, moissanite, CZ, GGG, and YAG all have their distinct style and flair which makes for gorgeous and valuable jewelry. 


How Do the 4Cs Affect Diamond Pricing?

Diamond prices are determined by their ratings across The 4Cs and a sense of where the diamond industry is overall (ie: the health of the economy, any current fashion fads, and if there’s any major diamond-giving holidays coming up). There are even diamond carat calculators that can help you understand the pricing. To help communicate the importance of the 4Cs in the diamond industry and diamond prices, we’re happy to share this sample price chart with you. 

Please remember that these prices as estimates and by no means are quotes or pricing promises made on the behalf of Diamocycle. 

This chart is meant to illustrate how being flexible in one of the Cs may allow you to find a stone that fits your dreams and your budget.   

Carat Dependent Pricing

Color Dependent Pricing

Color Dependent Pricing

What Else Determines a Diamond’s Price?

The other major determining factors of a loose diamond or diamond jewelery’s price are its condition, provenance, brand, and any unique features that might set your stone apart. 

Overall Item Quality & Condition    

The implicit “5th C” is the diamond’s condition and quality. Items that are banged up, scratched, or otherwise in a depreciated condition will obviously fetch a lower price. Items made from high quality materials in a new or like-new condition will obviously command a higher price than those that are not. 

LIkewise, as you look to buy a loose diamond or diamond jewelry, we encourage you to take into consideration an item’s quality and condition as you look for the best bargain for your budget. 

Item Provenance

The provenance of a loose diamond or diamond jewelry is its history of ownership: who has owned it previously and how its current owner acquired it. 

An impressive history can deeply affect the value of an important, large, or rare diamond, much like a piece of art. In addition, knowing the provenance of your diamond can help reassure buyers that the diamond was never acquired by unscrupulous means.  

Given the strong legislation around the mining of diamonds, we strongly recommend focusing your buying search around diamonds with a clear and recorded provenance. 

Item Brand

If the loose diamond or diamond jewelry you’re admiring has a brand name designer, such as Tiffany & Co, be warned that an identical piece with brand name recognition might cost more than a near identical piece without the brand name (and price tag). For example, a Cartier ring’s resale value will be higher than a similar item without the Cartier diamond brand.  

While many jewelry vendors usually price their loose diamonds and diamond jewelry on the resale value of the stones and material, some luxury brands are able to fetch a premium price in the selling. 

We encourage you to take an internal audit as to whether a luxury brand name makes a difference for you or the recipient of your gift and then guide your search accordingly.

 Also, if you buy a brand name item (and pay for that brand name premium, be forewarned that if you choose to resell the item, you may incur an even greater loss in the event that you are unable to recoup any of the significant brand markup you may have paid in the purchase of the item. 

Unique Features / What Makes Your Stone Special 

If the loose diamond or diamond jewelry you’re eyeing is unique in its setting or the stones themselves, that specialness will be noted in its pricetag. 

That said, it’s worth keeping in mind these unique features (and their additional premium) is often based on current fads and trends, so we encourage you to be mindful of the trends (and their pricetags) which you may either be chasing or actively trying to avoid. 

How Does the Diamond Supply Change Work?

From mine to retail store or place of purchase, a diamond often has gone through the following locations and points of sale: 

Diamond supply chain

This multifaceted path, too, absolutely affects the price of your loose diamond or diamond jewelry. Every time a diamond changes hands, an additional mark-up to deliver profit to the seller of the stone is added. 

As you consider an item, we encourage you to  attempt to cut out as many middlemen (or people) as possible, while acknowledging that many of the earlier links in the diamond supply chain are closed to those not in the industry. Similarly, we encourage you to keep in mind that lower wholesale prices are contingent on diamond dealers working with trusted business partners, which are relationships that are forged on decades of successful and mutually beneficial business operations. 

As a first-time or non-industry diamond buyer, some prices and opportunities may be closed to you by simply not being in the business professionally. 

Are Diamonds a Strong Investment?

As always with investing, there is always an exception to the rule. That said, overall, we generally do not recommend beginning investors select diamond investment as a cornerstone strategy for their portfolio. 

While we’ve been conditioned to believe diamonds are a strong investment over time, besides a small selection of specialized and rare color diamonds, the vast majority of commercial diamonds have actually decreased in value over time.

While graphs make it seem that diamonds have gone up in value, that increase in value is often outpaced by inflation and a small fraction of the growth that your money might have accrued via traditional investment means. In addition, the pressure from synthetic diamonds in the marketplace has also contributed to a lowering in price of natural stones when you’re looking to sell an engagement ring. 

However, if you are buying used diamonds as a way to invest or protect your money, we would like to remind you that the retail mark-up of a diamond often completely overshadows any small appreciation in value that you may enjoy over a significant span of time. 

In addition, besides a small selection of specialized and rare color diamonds, the expansion of the market has led to a small decrease in diamond value over time. 

For those looking to invest, we encourage you to use the rate of investment your money may have had in the stock market or another more traditional mode of investment as a handy benchmark as you consider investment in the diamond industry.

Tips for Buying Diamonds As Investment While we obviously recommend you to be careful and prudent in your investment strategies, if the thought of investing in diamonds still appeals to you, we strongly recommend you take the following tips into consideration. 

Understand Diamond Investment Basics

To state the obvious, you’ll make a profit on your investment diamond when the value of the diamond rises and you are able to easily sell your loose investment diamond at a price higher than the value at which you bought it. 

This model of making a profit on diamonds assumes a strong appreciation in value and a low barrier to selling at a higher cost. Holding these elements as the essentials to selling an investment diamond to a broker or trader. Let’s look at each variable independently. 

The Three Essentials to Make a Profit Investing in Diamonds 

  1. The Cost Basis: Buy at a Favorable Cost Basis

If you’re planning to purchase your investment diamond from a middle-man such as a diamond broker or jeweler, you’re likely to be a significant mark-up on the stone. As we’ve mentioned, this markup helps the diamond broker recoup their own investment and make a profit on the stone. 

With that in mind, the addition of the broker mark-up on the diamond will make it significantly harder for you to make a profit on the purchased stone as the value of the diamond will have to appreciate significantly to cover both the value of the diamond and the markup you paid.  

2. The Value Appreciation: Don’t Assume Diamonds Always Appreciate and Know Which Diamonds Will.

Here are some factors to keep in mind to temper your assumption that diamonds always appreciate in value. 

Changing Styles

While diamonds may increase in sentimental value over time, there’s no guarantee that they will increase in fiscal value. Decades old diamonds often have outdated cuts and proportions that are not as marketable as compared to modern diamonds which have been developed with updated industry proportions. As diamond technology is always improving, antique cuts and proportions may actually hinder your attempt to make a profit on the sale of an older investment diamond. 

The Diamond Market Itself 

Diamond prices have historically appreciated over the last 25 years, but at widely different percentage returns based on the stone’s fundamental attributes. Assuming a comparable cut, color, and clarity – a larger carat investment diamond commands a significantly higher price. Similarly, the price per carat of selling an investment diamond to a broker increases significantly with a higher color and clarity combination. 

3. The Sell Value: Sell High, Easily. (Easier Said Than Done). 

As we’ve discussed, it’s not always a given that you’ll be able to sell your investment diamond and make a profit on it. The biggest challenge to you will be finding a broker or trader who wants to buy your diamond (and usually only for the stone), who also trusts you, and is willing to pay the price you’re hoping to command. In comparison to a buyer buying from a store, you as an individual offer less trust, no flexibility in selection, and no additional services (sizing, appraisal, insurance), which makes your sale a challenging one. 

Often that challenge is met with the broker or trader offering a reduced rate, which again, makes recouping the amount on your investment challenging. Not an easy feat, but it can be done! 

Check out our Diamocycle Guides on Selling Your Diamond to learn more. 

Understand the Current Diamond Market

Part of being able to buy (and then sell) a diamond for profit is based on understanding some baseline facts of the diamond industry. 

A few secrets of the diamond market industry that we’ve learned over the years are: 

  • Rarer diamonds are actually harder to sell. 

  • Medium quality diamonds (with no visible discolorations or obvious imperfections) are actually easier to sell, as there’s more people who might buy them. 

  • Avoid Fads. 

    • When Considering Shape: 

      • While Princess cuts are hot right now, they will shortly be passé. 

      • Likewise, other unique shapes like Hearts and Marquise are also passing fads. 

      • Instead, we encourage you to invest in round brilliant cut diamonds, as they have the longest staying power and will command the most consistent price across the years, when you finally decide to sell your investment diamond. 

    • When Considering Color: 

      • While pink color diamonds are currently in vogue, their rarity and relative newness may also make them harder to resell in a handful of years. 

    • When Considering Cut: 

      • Pay attention to the cut of your investment diamond. 90% of round diamonds are poorly cut. 

      • Wise buyers buy non-traditional “Ideal Cut” diamonds that will fit into the new GIA and AGS best cut standards and offer you a greater potential for making your money back in the long-term when you sell your investment diamond.

  • Currently:

  • There’s a shortage of freshly mined rough material in larger sizes. Due to the scarcity of rough diamonds, most private diamond traders are always looking for larger stones in traditional or modern cuts of good quality. 

Understand Your Other Investment Options

While most of this article assumes that you’re purchasing the physical diamond itself, we want to highlight some other ways you can invest in diamonds along with the pitfalls of investing in physical diamonds yourself. 

The various ways you can invest in diamonds are by buying physical diamonds, investing in mining stocks, or putting capital into an investment fund. 

Here’s a few points of Diamocycle insight for investing in mining stocks and investment funds: 

Mining Stocks 

With all of this in mind, mining stocks are another way to benefit from the projected lack of supply vs demand in terms of rough diamonds. That said, your return on investment is heavily dependent on the quality of the individual mine in which you’re investing. If you’re looking to invest in a diamond-related fund, we strongly recommend you examine a diversified fund of physical diamonds, as mining stocks are completely reliant on the follies and fortunes of one individual mine. 

Diamond Investment Funds

In our estimation, a diamond investment fund is the best way to safeguard your investment and turn a profit while investing in diamonds. A diamond investment fund provides liquidity and a diversified portfolio. That said, each diamond investment fund is unique and must be evaluated on an individual basis. Some funds deal strictly with diamonds of a certain size, color, or finishing. 

We strongly recommend investing in a diverse fund to prevent overexposure to any portion of the market. Our favorite funds invest in a range of white diamonds in the 1.00 to 5.5-carat range, given the lasting demand and popularity of round diamonds in this size and color. Lastly, diamond investment funds can offer a strategic hedge to existing investments and a diversified portfolio can limit the downsides of over-investing in one segment of the market. 

Disclaimer: Diamocycle is not offering advice regarding purchasing diamonds as a way to make money. Diamonds are an extremely illiquid luxury asset class and are difficult to sell even by people in the diamond trade. The opinions we offer are not meant to be taken as for-profit advice, and individuals should not purchase diamonds unless they are prepared to lose a portion of their capital. 


There are as many places to buy diamonds as there are the stones themselves. That said, below are some common places to purchase used diamonds or diamond jewelery and the considerations to take with each. 

Buying Used Diamonds at a Jewelry Store

A brick-and-mortar jewelry store is one of the most traditional and trust worthiest places to buy a diamond. Given that your local jewelry store has likely been in business for a number of years, it’s worthwhile to trust the quality of the inventory and the trustworthiness of their practices. 

Many jewelry stores often have an on-site gemologist to verify their inventory, and who can speak knowledgeably about any used diamonds or diamond jewelry that catch your eye. 

That said, because all items on sale are in-store, your selection may be limited and the mark-up may be significant, as brick and mortar stores often have the highest operating costs due to their physical location and various overhead costs. We recommend buying from a physical jewelry store if you’d prefer to see items in person and don’t mind the substantial mark-up that comes from buying from a brick-and-mortar location. 

PROS: Strong Business Practices

CONS: Limited Inventory & Significant Mark-Up 

Pawn Shops & Diamonds

While pawn shops may seem to be plentiful and have a deep inventory of preowned and previously owned wedding rings, overall, we do not recommend buying a diamond from a pawn shop. 

While it may be fun to browse a pawn shop’s used wedding rings and see what they have in stock, we do not recommend buying a used diamond or piece of diamond jewelry from a pawn shop unless you have a way to independently verify the authenticity of the stone or if you are willing to purchase an item that may look amazing but may not be an authentic diamond or have the paperwork to prove its veracity. 

Pawnshops are in the business of giving short-term loans to people who may need to bring in their items for a quick cash offering. While you may find a seeming steal or bargain at a pawn shop, we remind you that pawnshops often do not have trained gemologists on their staff to do ring or diamond appraisals. What may seem like a bargain may also not be a verifiable stone. 

At the most basic level, pawnshops make their profit by buying valuables, such as loose diamonds and diamond jewelry, at the lowest price possible, and then marking that item up, to sell, for the highest price they can. 

PROS: Discounted Pricing, Easily Accessible

CONS: Limited Safeguards for Consumer Protection and Item Veracity 

If you are set on buying a used diamond or diamond jewelry from a pawn shop, we encourage you to keep these tips in mind: 

Tips For Buying Diamonds From A Pawn Shop

Do Your Research

Before you go pawn shop jewelry shopping, we strongly recommend learning more about the jewelry and jewelry style you are searching for. Go to your local jewelry store and try on your intended style to familiarize yourself with your tests, the feel of authentic jewelry, and what retail prices are like. This will better equip you to pick your item and get a good deal at your local pawn shop. 

In addition, we strongly recommend researching the pawnshop at which you plan to shop. Get a sense of the company’s reputation, its prices, and its willingness to negotiate. If you can, prioritize visiting pawn shops that specialize in jewelry. Lastly, we recommend that you google the market price of gold (per gram). It’s always helpful to keep that in mind as you go shopping for a piece. 

Think Outside the Box

If you are searching for an exact style or type of item, odds are you’re going to be in for a very long search. Most of the delight in shopping at pawn shops is similar to that of shopping at a thrift store: you never know what you’re going to get!

With that in mind, we also encourage you to be creative in your search. If you’re looking for a ring, we’d encourage you to also look at necklaces and other items. You may be able to find a stone (set in a different jewelry type) that could be the pawnshop jewelry find, that you bring to your jeweler to reset, and from there you’ll end up with the item of your dreams. 

With jewelry, we encourage you to be less concerned with the aesthetic of the piece, and instead focus on the quality of the stone or used diamond in the piece. If the jewel is in excellent condition and of excellent quality, you can bring the item to your local jeweler to have them reset your pawnshop jewelry find at a fraction of its retail price. 

Prepare Yourself to Negotiate

One pro of pawnshop jewelry buying is that you can negotiate with your pawnbroker. In addition, if you pay in cash you’ll likely be able to procure an additional discount. As you may know, the best way to negotiate is to be willing to walk away.  Before you go to a pawn shop, we recommend brushing up on some negotiation tactics to get you the best deal for your future loose diamond or diamond jewelry. 

See If There’s Anything You Might Trade

In addition to negotiating, shopping at a pawn shop for jewelry offers you the opportunity of potentially trading in an old item for something in the pawn shop’s inventory. Bringing in an old item of yours not only helps you get rid of unwanted items but also will likely get you a discount on any item that catches your eye. 

Trust Your Gut

As you may know, all valuable fine jewelry should come with papers from a gemologist to back up its value. If your pawnshop with jewelry doesn’t have the necessary papers to verify the value of your diamond jewelry, we suggest you move on to another pawnshop that offers items with gemologist reports. In addition, if the pawnbroker is pressuring you to make a sale or buy an item, we again suggest walking away. If you don’t feel comfortable making the purchase, don’t. 

Remember the Risks of Pawn Shops

In addition, most pawn shops with jewelry do not have the ability to tell if a diamond they have bought has been treated or is synthetic. The pawnshop may seem like they have many gorgeous engagement rings, but you need to do your research. It is exceedingly rare that a pawn show can do a pawn shop jewelry appraisal. With that in mind, despite the aforementioned perks of pawnshop shopping, we strongly recommend that you only buy your item from a reputable seller or require that any piece you buy has an attached GIA certificate. 

While some pawn shops for jewelry specialize in diamonds and have a gemologist on staff, this is exceedingly rare.  If you have extensive knowledge in the diamond and gemology industry, a pawn shop can be an incredible place to find amazing items and deals on diamond jewelry. That said, unless you are a diamond expert, we encourage you to consider the risks in buying a diamond at a pawn shop, even a pawn shop specializing in jewelry. 

Used Diamonds at Fine Auction Houses

Fine Auction Houses are wonderful places to buy high-value diamonds and 2nd hand diamonds, such as a 3-carat diamond cut platinum ring, often at prices upwards of $100,000. 

While we strongly endorse browsing and purchasing from a fine auction house as one of the best places to buy used diamond rings, we also acknowledge that the caliber and price tag of items being sold at a fine auction house may not be aligned with your budget. 

Given their reputation, you should feel assured that any used diamond or wedding ring you’re buying from a fine auction house is truly what the auction house says it is. That said, with fine auction houses, there is a significant barrier to entry given the high price tag (and considerable mark-up) of the diamond rings and used diamonds that are being sold.

PROS: Strong Industry Reputation & Remarkable Inventory

CONS: Prohibitive Pricing and Top Luxury Goods

Can I Buy Diamonds on EBay & Other Non-Diamond Specific Online Marketplaces?

As you search online, you may be tempted to buy a value diamond ring online from a website such as eBay, Facebook Marketplace, or Craigslist. 

While there may be some incredible deals and 2nd hand diamond rings on these online marketplaces, we would like to remind you of the risks inherent in buying and selling diamonds on such online forums. 

Given that eBay, Facebook, or Craigslist do not employ gemologists, there is no way to verify that the used engagement ring or a 14k wedding band listed online is actually the item being sold to you. Beyond that, even if the item matches its description, there is no way, such as a resale diamond value calculator to ensure that the price being offered is fair or that the transaction is being conducted in a safe way. 

Furthermore, given the relative risk of meeting someone offline and the high value of items (both the diamond and the cash being exchanged),  we strongly urge you to exercise the utmost caution should you decide to buy a used diamond from someone off a marketplace that then requires you to meet in person. 

While some vendors on eBay have reviews that may make the purchase seem safe, we urge you to be wary and careful when purchasing from a large online marketplace lacking safeguards to verify stones or protect their buyers. While we understand that the allure and the navigability of such a website and the inventory of pre-owned diamonds are significant, we encourage a strong level of caution when exploring buying a used diamond from an unknown online seller. 

PROS: Easy to Search, Large Inventory at A Variety of Price Points

CONS: No Industry Professional Accreditation, No Way to Verify Purchase, Risk Inherent in Platform of Purchase

Critics’ Pick: Diamond Specific Online Marketplaces

In terms of buying from a vendor with an admirable intersection of value and expertise, our vote is to buy from diamond-specific online marketplaces. This may include online auction houses and other diamond and jewelry-specific online marketplaces (Diamocycle Marketplace, Blue Nile, etc) that exclusively sell diamonds online.

Buying from an online diamond-specific marketplace has several advantages. Because the institution is strictly online, the price to buy your diamond online does not include the heavy mark-up that brick and mortar retailers must charge to cover their overhead. Online diamond marketplaces are instead able to offer a selling price closer to the wholesale price of the diamond as they have lower overhead and business costs. 

Additionally, at a diamond-specific online marketplace, the survival of their business is dependent on excellent customer service and high-quality inventory. (The only thing they’re selling is diamonds!) As a result, even though you’re unable to physically experience the stone prior to purchase, you can rest assured that the quality of the diamond is appraised, verified, and accurate. In addition, many diamond-specific online marketplaces employ a gemologist and offer GIA certificates to reduce and address any apprehensions a consumer may have from buying a diamond online. 

Lastly, given their online status, most diamond-specific online marketplaces have a substantial searchable online marketplace, allowing you to truly find, search, and purchase a stone that matches your specifications and your budget. Online diamond marketplaces take pride in offering a wide selection and reasonable prices, and you, as the buyer, are sure to benefit from their online business model. 

If you know what you want, an online diamond marketplace is an excellent way to find a superior diamond or jewelry (sometimes pre-owned or secondhand) at a reasonable price. 

PROS: Great Selection, High Quality, On-Site Gemologist for Authenticity

CONS: Not Being Able to Experience Item in Person 

Can I Buy Jewelry from My Friends?

Lastly, you can always buy a used diamond or ring from someone in your known social network. Even though you may be buying from someone you know, we still strongly encourage you to ask for the corresponding GIA certificate for the stone. 

Buying from within your social network may be complicated if the used diamond you’re buying is a pre-owned engagement ring from a previous relationship, untimely death, or other tragedy. If having your friend see you wear their preloved 14k wedding ring brings up complicated or unpleasant feelings, no matter the price or the need to sell the diamond, it may not be worth the purchase. In addition, asking to appraise and verify the diamond with an outside source may add stress to the friendship, but we only encourage you to engage in such a venture with a friend who would respect your consumer rights as much as you respect the friendship. 

Lastly, individuals are usually only selling select items that they have in their possession. We encourage you to truly examine what kind of second-hand jewelry is for sale you want and make sure the pre-owned diamond being offered to you matches what you were shopping for. 

That said, the ability to support a friend and buy a preloved diamond ring at a personal discount may be a once-in-a-lifetime opportunity. We simply encourage you to fully examine the situation, given the inherent social complexity and the potential impact it may have on your friendship. 

PROS: Trusted Source, Likely Good Price and Well Maintained Item

CONS: Social Complication, Very Limited Choice of Item


It has long been the eternal struggle and question of many a consumer: “Is my diamond real?” 

While the internet is full of myths and ways to determine if your loose diamond or diamond jewelry is real or fake at home, we’ve put together this resource that not only dispels the false myths surrounding how to tell if your diamond is real or fake but also offers real tips for ways you can determine the authenticity of your diamond. 

That said, please note, above all, we recommend bringing your loose diamond or diamond jewelry to a gemologist to obtain a GIA diamond certificate to tell you whether your diamond is real or fake. 

A lab, such as GIA, has the technology and expertise to discern whether your diamond is a natural diamond, diamond simulant, imitation diamond, or synthetic diamond. In addition, a GIA Diamond Report will not only identify the diamond, but also provide an unbiased analysis of the 4Cs of your diamond: color, cut, clarity, and carat weight.  

While our definitive Diamocycle Guide is no substitute for a diamond certificate from GIA, as always, it is our pleasure to offer you all the information possible to allow you to move through your life with confidence, clarity, and peace of mind.

Step 1: Understand What’s Diamond Myths & Proper Procedure

The first step to beginning to understand whether a diamond is real or fake is debunking and understanding what’s industry myth and what are the “false tells” of a fake diamond. Below are some common diamond myths and equally false ways to discern a diamond’s veracity. 

MYTH: A real diamond has inclusions. Fake diamonds are perfect. 

FALSE PROCEDURE: Use a jeweler’s loupe to examine your loose diamond or diamond jewelry. 

For the uninitiated, a jeweler’s loupe is a small magnifying glass used by jewelers in the industry. 

To begin, for the unskilled, it is rather difficult to spot inclusions (or imperfections) on a diamond using a loupe. Often the reflections and facet junctions can make it difficult to see inclusions. In addition, some loose diamonds are flawless and include no inclusions, making the use of the loupe or the assumption that inclusions mean a diamond is real an unreliable way to tell if your diamond is real or false. 

Beyond that, while most authentic diamonds will have inclusions, it would be incorrect to assume that imitation diamonds will not have inclusions. (They might be added in attempts to further promote “authenticity.”) In addition, some glass diamonds will have gas bubbles, which can easily look like natural inclusions. 

There are also many other natural gems (that include inclusions, but are not diamonds) that might look like diamonds to the non-professional eye. These gemstones include colorless topaz, colorless zircon, and colorless sapphire. Which is not to say, inclusions does not a diamond make and inclusions are not a reliable way of telling if your diamonds are real!  

MYTH: Synthetic diamonds are not real diamonds. 

FALSE PROCEDURE: A jeweler’s loupe is a good way of how to tell if your diamond is real (natural) or synthetic. 

Synthetic diamonds actually are real diamonds! Synthetic diamonds are man-made diamonds that have the same properties as natural diamonds. While the price between natural diamonds and lab-grown diamonds is considerable, it would be incorrect to consider synthetic diamonds as “fake” diamonds.

Lastly, as the physical properties between synthetic diamonds and natural diamonds are identical, it is impossible to tell the difference between a synthetic diamond and a natural diamond via loupe. The only way to determine the difference is via laboratory testing. 

While synthetic diamonds may not fetch you the same price as a natural loose diamond or diamond jewelry, we encourage you to remember that synthetic diamonds are diamonds too. 

MYTH: Real diamonds have sharp edges and fake diamonds will not. 

FALSE PROCEDURE: Examine your loose diamond for sharp edges. If it has them, it’s a real diamond. 

Given the high price of gold and platinum, some valuable natural diamonds are set in silver, and antique diamond jewelry is often set in a mix of gold and silver. Given the variety of metal settings for both natural diamonds and imitation diamonds, we strongly discourage you from using the setting metal as a gauge of whether your diamonds are real. 

While one might assume that a high-quality diamond jewelry setting belies a high-quality stone, a poor quality setting might be holding a natural authentic diamond, and simply have survived a lot of wear or tear or be a result of the work of a shoddy jeweler. 

MYTH: You can determine a natural diamond by the quality and metal of its setting. 

FALSE PROCEDURE: Examine the quality of the setting to determine the authenticity of your stone. 

While some may believe that natural diamonds are exclusively set in valuable metals, such as 12k white gold ring, the setting metal is an incredibly inconsistent and inaccurate way of how to tell if your diamond is real. 

Given the high price of gold and platinum, some valuable natural diamonds are set in silver, and antique diamond jewelry is often set in a mix of gold and silver. Given the variety of metal settings for both natural diamonds and imitation diamonds, we strongly discourage you from using the setting metal as a gauge of whether your diamonds are real. 

While one might assume that a high-quality diamond jewelry setting belies a high-quality stone, a poor quality setting might be holding a natural authentic diamond, and simply have survived a lot of wear or tear or be a result of the work of a shoddy jeweler. 

MYTH: Diamonds can’t be scratched.

FALSE PROCEDURE: Rub the gem with sandpaper. Real diamonds won’t be scratched. 

This is a damaging test and should never be used! As the hardness of sandpaper ranges from 7 to 9 on the Mohs scale, it can often damage a diamond, whether it is natural or not. With the value of your loose diamond or diamond jewelry in mind, we strongly recommend never attempting “The Sandpaper Test,” as you can damage your stone, further devaluing it, regardless of whether it was real or not. 

MYTH: Natural diamonds can’t be broken by heat. 

FALSE PROCEDURE: Fill a glass of water with cold water. Heat the stone for 40 seconds and then drop the stone in cold water.  If the stone shatters, it was made of weaker components and was not a real diamond. A true diamond will show no reaction. 

As diamonds are made of incredibly strong materials and are unresponsive to heat, technically, this is a way you can use in how to tell if a diamond is real.  

That said, as mentioned, synthetic diamonds are diamonds too, and this test will not differentiate between natural and synthetic diamonds. In addition, we encourage you to use this test sparingly, as it will destroy the stone you have, if it was not a real diamond! We encourage you to consider whether the truth is worth the possible destruction of the loose diamond or diamond jewelry you have. 

While it is true that imitation diamonds that are made in a mold (often plastic or glass) lack sharp edges, synthetic diamonds and other imitation diamonds made from other gems will also have sharp edges. 

Thus, while you can use “The Edge Test” to tell gemstones from molded items, you can not use the edge test to tell between natural diamonds, other gemstones, and synthetic diamonds, rending “The Edge Test” an unhelpful tool in trying to figure out if your diamond is real. 

MYTH: Real diamonds will not fog. 

FALSE PROCEDURE: Breath on the diamond. If it fogs, it’s not a real diamond. 

This is an incredibly unreliable way of how to test a diamond. Beyond that, there is no articulated guideline on how long one should breathe or how large the diamond surface must be.

While natural diamonds will not fog, synthetic diamonds will behave the same way (also not fogging), further obscuring the results of your very unreliable test if you’re trying to understand if your diamond is natural or not. In addition, ambient humidity might affect your results, further complicating the reliability of this test. 

MYTH: Real diamonds “sparkle.” 

FALSE PROCEDURE: Check for the sparkle. If it sparkles, it must be a diamond.  

While there is specific sparkling that jewelers refer to in loose diamond or diamond jewelry (it’s called scintillation), it is incredibly difficult to discern the scintillation of a diamond from the sparkle of an ordinary gemstone. To the untrained eye, many faceted gems, such as synthetic moissanite, synthetic cubic zirconia (CZ), or a colorless natural zircon will sparkle in a way that is similar to a diamond’s scintillation. 

What is scintillation? 

A natural diamond’s scintillation refers both to its sparkle and the pattern of light and dark that is caused by areas of reflection within the loose diamond or diamond jewelry. Along with scintillation, other factors that you might see in a diamond’s “sparkle” include the diamond’s brightness (the external and internal white light that are reflected from a face-up view), and fire (how the white light scatters like a rainbow). That said, both brightness and fire are qualities that both diamonds and other gemstones have, making them unreliable factors for determining a diamond’s veracity. 

 What makes a loose diamond or diamond jewelry shine? 

To further convince you why scintillation is a poor judicator in how to deal if a diamond is real, a diamond or gemstone’s scintillation also depends on the following factors: 

  • Cutting Style: Even if two diamonds have the same number of facets and the same shape, the cutting style will play a crucial part in the brightness of the diamond, making brightness an inaccurate way of how to test a diamond.  

  • Number of Facets: The more facets a diamond has, the greater its ability to bounce and scatter light. An imitation diamond with more facets may shine far more than a natural diamond with a lower facet cut. Again, the perceived sparkle of a diamond is an inaccurate way of how to test if a diamond is real.  

  • Cut Quality: Likewise, a poorly cut natural diamond is still a diamond, but may not deliver the same shine that you’d expect of natural diamond. Just because it doesn’t sparkle, doesn’t mean it’s not a diamond. 

  • Lighting: A change of lighting will absolutely change the sparkle of the stone you’re holding. Again, do not rely on the sparkle of the diamond to decide whether it’s real or not (it might just be your lighting!). 

  • Cleanliness: Lastly, the cleanliness of your diamond will affect its shine, again making shine an unreliable decider of whether your stone is authentic or not. 

MYTH: You can’t see through a real diamond. 

FALSE PROCEDURE: Look at a newspaper through a diamond. If it’s a real diamond, you won’t be able to read the type. 

Again, this is a problematic test in how to tell if your diamond is real. The faulty logic assumes that a well-cut diamond is highly refractive, which would cause the light to bend as it moves through the loose diamond or diamond jewelry. 

While this is a test that works well for gemologists, it can be very confusing for unskilled professionals. It should never be used as a deciding way of how to test a diamond, as many variables can affect the reading of the newspaper. To give you a sense of how fickle this test is – some factors that affect “The Newspaper Test” are the lighting conditions and surroundings, the cleanliness of the stone, its placement on the newspaper, the tester’s eyesight, the mounting of the stone, and its shape and proportion. Given all that, please do not rely on a newspaper to decide anything about your loose diamond or diamond jewelry! 

MYTH: Real diamonds sink; everything else floats. 

FALSE PROCEDURE: Put your diamond in a glass of water- if it sinks, it’s a diamond. 

As diamonds have a high density, a real diamond will sink in a glass of water. That said, diamond substitutes and imitations have lighter densities and will float to the middle or top of the glass. That said, there are plenty of gemstones that are equally or more dense than diamonds, so while this test can tell you if your stone isn’t a diamond, it’s not a reliable way of how to test if your diamond is real and most definitely a diamond. 

MYTH: Real diamonds are always a deep blue under a UV light. 

FALSE PROCEDURE: Hold your diamond under a UV light – if is blue, it’s a diamond. 

Much like the water test, this can tell you if your stone is NOT a diamond, but is a little less conclusive as to if your stone is actually a diamond. Under UV light, most diamonds will reveal a blue fluorescence. While a medium to the strong color of blue confirms that you do have a diamond, not all diamonds reveal a blue fluorescence, again rendering this way of how to test a diamond helpful but not conclusive.  

Given the many diamond myths and false procedures, what’s a diamond owner to do? 


Below are a few viable solutions on how to test your diamond and see whether or not the diamond you have is real or fake. 

OPTION 1: Use a Thermal Conductivity Probe (aka “The Diamond Test”) 

Because diamonds are effective heat conductors, a real diamond will disperse heat rapidly after being warmed. With this in mind, using a thermal conductivity probe can be a helpful test in how to tell if a diamond is real. 

If the loose diamond or diamond jewelry disperses heat at a slower rate, the diamond is not real. That said, it’s worth noting that synthetic moissanite stones have a similar or equal heat disbursement as real diamonds, which renders this test inconclusive with moissanites. Given that, you may need to conduct a variety of tests to narrow down whether or not your diamond is real, natural, or synthetic. 

OPTION 2: Use a Electricity Conductivity Test 

Similarly, diamonds conduct electricity better than other stones, including synthetic moissanite. With this in mind, jewelers and gemologists often use an electricity conductivity test to determine whether a diamond is real or fake. An electricity test will provide conclusive results as a diamond will show conductivity while other stones, like moissanite and cubic zirconia will not. 

OPTION 3: Conduct High Profile Weighing

Another way that jewelers and gemologists determine if diamonds are real are with very finely tuned scales for measuring small differences in weight. Real diamonds will weigh less than fake stones of the same size. While this is a reliable method in how to test a diamond, it requires you to have a special scale for weighing carats and a fake diamond that is about the same shape to use as a comparison. 


Diamond vs. ______________ ? 

In this section of our guide, we articulate some of the most important differences between diamonds and other stones that look like diamonds. Our hope is that by combining the above tests of how to tell if a diamond is real with these specifics, you’ll be able to determine whether your loose diamond or diamond jewelery is real or fake. 

Diamond vs Moissanite

Given the remarkable visual similarities between diamonds and moissanite, here are a few ways to tell the difference: 

  • Via Microscope: At 1200x magnification, a diamond’s inclusions or the lack thereof on moissanite will become visible and a viable way to tell the difference. 

  • Electric Conductivity Test: As diamonds conduct electricity better than moissanite, this is a valid way to determine the difference. 

    • (Please note that a thermal conductivity test will not tell you the difference, as moissanite and diamonds have nearly identical thermal conductivities!) 

  • X-Ray Examination: Diamonds are radiolucent, while other stones suchs as moissanite, are radiopaque. Sending your stone to a professional testing center with an x-ray machine is a very reliable way of telling if a diamond is real. 

Diamond vs Cubic Zirconia

  • X-Ray Examination: As mentioned above, Cubic zirconia is also radiopaque, making an x-ray examination a viable way to determine the veracity of your stone. 

  • High Profile Weighing: Cubic zirconia weighs more than diamonds, allowing you to conduct a weight test if you have two stones of similar size. 

  • Light Reflection: Cubic zirconia also reflects orange tinted light, as compared to the shades of grey that are emitted by diamonds. 

  • Presence of Inclusions: Cubic zirconia often doesn’t have inclusions, while diamonds often do. As per above, this is not a conclusive way of how to test a diamond across the board, but can help determine if your stone is cubic zirconia or not. 

Diamond vs White Sapphire

  • Sparkle and Contrast: While white sapphires often look like diamonds, white sapphires will not have the standard contrast of light and dark areas that a diamond has, and often also lacks the diamond’s signature sparkle. If the light and dark parts of the stone seem to be blurred, odds are high you may have a white sapphire.  

Diamond vs White Topaz

  • Scratch Test: While white topaz might look like diamond at first glance, topaz is softer than diamond and much more easily scratched by other materials. If you look closely at the surface of your gemstone and see scratches, odds are it is not a diamond, but instead a stone such as white topaz. 

Natural Diamond vs Synthetic Diamond

Given that synthetic diamonds are diamonds, but differ greatly in resale value and pricing, it’s both essential and incredibly difficult to tell the difference between a natural diamond and a synthetic diamond. 

  • Conductivity Test & High Magnification Examination: Given the difficulty of telling the difference between synthetic and natural diamonds, we recommend a combination of these two professional tests to see if your diamond is synthetic or natural. 

As always, the world of loose diamonds and diamond jewelry is fascinating, complex, and full of beauty. As always, we strongly recommend obtaining a GIA certificate to ascertain the veracity of your diamond, and contacting us should you ever need any assistance or further information in determining next steps for your stone. 


Here’s our our list of top tricks and tips to have a safe, successful, and budget-conscious experience buying a used diamond or preowned diamond jewelry.

Buy from a Source You Trust

When you buy from a diamond seller you trust, you’re eliminating a layer of anxiety and risk from an otherwise stressful process. Take the time to read reviews, research, and understand the business model of your diamond seller. Take some time to consider if you would mind buying a preowned diamond ring. 

That way, once you’re ready to buy, you’re not second-guessing the authenticity of the seller or the stones and you can simply focus on what matters.

Keep Your Priorities In Mind

It is always possible to have a bigger, sparklier diamond. In the excitement of shopping,  it’s easy to forget what your authentic tastes are or what price limit would be best for your budget. Before you begin shopping – know your limits and your priorities. 

A few questions to keep in mind are: 

  • Are you willing to buy a used, pre-owned, or preloved diamond? 

  • What’s your highest limit for budget?

  • Do you want something you’ll wear every day?

  • If so, is this an item you feel comfortable wearing every day?

  • Does this item feel like an accurate representation of the relationship or sentiment you were hoping to celebrate? 

Never let yourself feel pressured into making a purchase. Your diamond ring seller is there to support you! And should you ever feel yourself getting overwhelmed, never hesitate to ask to take a moment or return another day. 

Understand Diamond Pricing Once you have your budget in mind, we encourage you to remember how diamonds are priced. Given that most diamonds are priced across 5 factors (the 4Cs and its condition), we encourage you to prioritize what qualities you would like in a new or used diamond. 

Given that the most apparent factors are size and cut, we recommend setting a budget and a carat and cut goal. From there, we’d suggest having a bit of flexibility in diamond color, clarity, and condition. 

While a sizable stone might look “yellow” or “dingey” next to a perfectly clear stone – we remind you that when you’re staring at the stone without flawless comparisons, you still may feel delighted and awestruck by its beauty. Similarly, while inclusions and flaws seem horrifying while looking through a loupe, some small imperfections will absolutely go unnoticed from the other side of a brunch table with your friends. 

If you’re willing to accept a preloved diamond or used engagement ring with a small flaw or a slight change in color, you may be able to score a stone that has the size and cut style that you most desire while still remaining within your budget.

That said, we truly advocate for getting a diamond (used or new) that you find beautiful and fills you with joy. We simply encourage you to remember and consider that the new or used diamond you buy doesn’t have to be perfect on all accounts – it simply needs to shine strong and bright for you. 

Consider Your Recipient’s Taste If you’re buying a diamond for someone other than yourself, we recommend that along with keeping in mind the intricacies of the diamond industry and your budget, that you keep in mind your recipient’s sense of style and taste.

Prior to going shopping, you may want to discreetly ask their friends what kind of styles or types of jewelry they prefer to wear. Likewise, as you begin to consider the type of purchase you might like to make for your recipient, we encourage you to start to pay attention to the kind of jewelry and items they like to wear. The best gift is usually a piece that is in line with the styles they have, but has some unique aspect or new element to it. 

Lastly, as you begin the excitement of shopping, please remember and consider their tastes first, not your own! If the aim of your gift is to bring joy to a loved one, remember that they’re the one wearing the item. Your generosity will serve you best if you select an item that is well proportioned and aligns to their taste.

HOW TO GET THE BEST BARGAIN ON A USED DIAMOND As you move forward with your diamond buying process, here’s a few final tips to help you get the best used diamond for your budget. 

1. Research & Arm Yourself with Knowledge

The best way to get a deal is to understand the diamond industry, the type of used diamond or diamond jewelery you’re looking for, and the best places to buy a used stone to ensure your purchase is a success. 

2. Buy from the Right Vendor

The best way to get a bargain is to buy from the right platform and vendor. We strongly recommend buying from a secure online platform that specializes in used diamonds and diamond jewelry. By picking the right context in which to purchase a stone, you’re setting up the architecture of your search for success. 

3. Be Patient

Finding a steal requires patience and fortune rewards those who wait. We recommend having your funds ready and jumping when a deal crosses your path. By equipping yourself with knowledge and limiting your search to selling platforms you trust, you’ll be able to see the deal when it occurs and that perfect stone will be yours. 

4. Buy Verified

Above all, we cannot stress enough the importance of buying a stone with a GIA Certificate or one that is GIA preferred and inspected by a third party. By ensuring that you’re buying verified, what you think you’re buying is actually what you’re buying. Nothing ruins what seems to be a “steal” as being the one who’s been stolen from. If it’s too good to be true, it probably is. 

 Buying used diamonds or diamond jewelry can be an exciting and exhilarating process. With the above guide, we hope that we’ve transformed the process into one that feels clear, manageable, and a bit exciting. There are gorgeous used diamonds out there- just waiting. We wish you well on your search.

Your Neighborhood Jeweler,