Buying diamonds isn’t a simple thing – to really ensure you’re getting a quality stone or piece of jewelry you need to know how to buy diamonds correctly.

Before we start, this is a long guide we know, but every single part of it will make you closer to get the best diamond, as well as will allow you to save more $$$ by knowing the ins & outs of this industry.

So, in this guide we’ll see how to buy diamonds like a pro! It’ll help you save money, avoid diamond scams and know how to spot a fake with ease.

And the best part is you don’t have to be a gemologist or get some fancy degree from the GIA (Gemological Institute of America) to be diamond buying expert, bring a cup of coffee, and let’s start!

Table of Contents:

Introduction: Diamonds Are Forever

Definitions & History


The word “diamond” comes from the ancient Greek Adamas which broadly means “unbreakable” – a quality that points to its hardness. A diamond’s strength is generally what makes it one of the most sought-after gemstones on earth – besides its beautiful light dispersion qualities, of course.

It’s also a quality that a famous De Beers advertising campaign used to popularize Frances Gerety’s famous 1947 copywriting slogan: “A Diamond is Forever”.

This slogan would become the singular reason why diamonds would be expected on nearly every engagement ring worth having in America. This and the other N.W. Ayer agency campaign to get diamonds on all celebrities and all catwalks possible. So as expected, diamond sales went through the roof.

The ‘slump’ decades were gone – at least for the diamond industry.

Fast forward to today and what do you know – diamonds are still the ‘stone’ of choice. Actually, diamonds are the ‘stone’ that everyone implies when they talk rings.

Why Learning How to Buy Diamonds is a Lifelong Skill

Diamonds are the proverbial girl’s best friend, no doubt!

We use ‘proverbial’ here because that friendship has spread to both men and boys too. Everyone loves diamonds.

Men think about diamonds, and not just for the engagement ring they need to buy when they go down on one knee, but also for their own jewelry and other gifts.

But beyond that more and more people are seeing the value of investing their money in diamonds and other stones and precious metals as a store of value (that needs to be taken with a grain of salt, diamonds don’t store value as people would think)

There are only a finite number of real diamonds that are mined in the world – and they take thousands of years to form. So buying loose diamonds is a favored option of many people due to diamonds uniqueness, compared to other jewelry.

Since diamonds are highly coveted by both women and men alike, there is a lot of money to be spent and made in the diamond trade. Anytime a lot of money is involved, there is a serious potential for theft, scams and other nefarious dealings.

That’s why there is great need for guidance on exactly what, how and where to buy the best of it – exactly what you’re about to learn. Let’s get started.

The Basics of How to Buy Diamonds

Knowing the 4 “Cs” of Diamond Buying

When buying diamonds, it is best to ensure that you know a bit about diamonds, and the best way to understand diamonds is to understand diamond language.

The most basic aspect of diamond language is the 4Cs.

The 4Cs of Diamond Quality is the globally accepted standard for assessing and describing diamond quality. It includes: Color, Clarity, Cut, and Carat Weight.

Up until the mid-twentieth century, there was no standard way of judging diamonds. And in a rapidly growing industry at the time, a universal language was needed to communicate diamond quality among industry insiders and to diamond buyers.


As diamonds grow inside the earth, certain changes in chemical composition alter their color.

Color evaluation of diamonds is largely based on the absence of color. This is because the most chemically pure and structurally perfect diamonds are colorless. The GIA measures a diamond’s degree of colorlessness through the use of a 12-letter alphabetical scale of D to Z.


A diamond on the D side of the scale has the least amount of color and is considered ‘colorless’, meaning it has no color at all, while one on the Z side has the light tones.

All D-Z diamonds are referred to as ‘white’ even though they have varying degrees of color. This is because their color distinctions are so slight that they are invisible to an untrained eye.

But make no mistake – these distinctions largely affect a diamond’s quality and price. A diamond with a tone that’s deeper than the Z threshold is considered a ‘fancy-colored’ diamond.

As you may suspect, such diamonds (the fancy ones) are extremely rare and are graded on a separate color scale. And this shoots their prices way higher than those of their ‘colorless’ counterparts.

It’s important to note that when mounted, a diamond’s color is affected by the metal adjacent to it, meaning that getting a gold setting will make diamond a bit “yellow”, so be careful here picking the right setting.


While diamonds are being formed, they acquire a number of intrinsic characteristics called ‘inclusions’ and ‘blemishes’ – former being internal and the latter being external. Diamonds are evaluated through the close examination of these characteristics and how they affect the appearance of the stone.

The GIA 11-point clarity scale ranges from ‘flawless’ to ‘included’ with markers on the amount of inclusions and blemishes present that a naked eye would find impossible to see.


The closer a diamond is to ‘perfection’, the higher its value & price. But any treatments or enhancements done to a diamond to improve its ‘perfection’ lower its value (some techniques are used to enhance color & clarity, like laser drilling and fracture filling).

Check out our detailed guide on diamond clarity to learn more.


Contrary to what you might think, ‘cut’ refers to a diamond’s proportions and symmetry vis-à-vis their interaction with light, and it’s not what people confuse cut with, that’s the shape!

These are the very characteristics that give diamonds their magnificent shine. And they are also the characteristics that make a diamond’s cut the most complex to analyze out of all the 4Cs.

This illustration tells what cut means, and why it’s important to get highest grade possible:

Diamond cut and light reflection


What people usually refer to as cut (when you hear them saying round cut diamond) is actually the shape, here are the most common ones:


Precise workmanship is required to give a diamond the required facet shapes, angles, girdle width, culet size, polish and symmetry that render it top-graded in brilliance, fire and scintillation.

Too many technical terms ha? That’s why cut is considered the MOST important factor among the 4Cs, and it’s never “too high” grade when it’s about the cut!

Beyond all that jargon, the basic idea is that the GIA cut scale for standard round brilliant diamonds in the D-to-Z color range has 5 degrees ranging from ‘excellent’ to ‘poor’.

Carat weight

Carat weight is the measure of how much a diamond weighs. The word “carat” comes from the carob seed which was the original unit of measure used by diamond traders. It should not be confused with “karat”, which is used to refer to gold’s purity.

In short, a diamond carat is equivalent to 0.2 grams, to put this a bit in perspective, paper clip is 1 gram, which is 5 carat.


In order to allow very precise measurements, a carat can be sub-divided into 100 points. This way, a jeweler can call a 0.35 carat diamond a ‘thirty-five pointer’. Above one carat, diamonds, decimals are used. So a 1.02 carat diamond would be referred to as ‘one point oh two carats’.

It is important to remember that carat weight is never used in isolation to determine a diamond’s value. Two stones with similar carat weight could be priced very differently depending on the other variable factors – cut, color and clarity.

Another thing to note is that as a diamond’s carat size increases, its price increases at an increasing rate. This is tied to the fact that larger diamonds are rarer.

So as the carat weight goes up, your bill will increase not only in total but also on a price-per-carat basis.

Understand the Diamond Buying Process

No More Uncertainty, Embarrassment and Over-Paying

Buying diamonds can be a dizzying experience. Especially with the wide ridiculous array of natural diamonds types vs synthetic diamonds and crystal-clear types vs colored ones.

But it doesn’t have to be.

Once you understand the grading criteria and various other tidbits about diamonds, the buying process can run smoothly and painlessly. Before we jump straight into the particulars of the buying process, here are an important thing you need to know about diamonds.

Diamonds vs. Other Gemstones

The first thing that makes diamonds unique is that they are the only gem formed from a single element. All other gems are combinations of two or more elements. When it comes to durability, very few gemstones stand a chance against diamonds.


Since they can only be scratched by other diamonds, they maintain their polish extremely well. So it comes as no surprise that only 20% of diamonds are used as gemstones while the rest are used for industrial purposes. As gemstones, diamonds are well-suited to daily wear and tear making them the perfect choice for engagement or wedding rings.

When it comes to the gemstone industry, you should know that diamonds do not respond to normal market pressures like other gems. Diamond prices hold high due to artificial market pressures. This has a lot to do with a single company that is a near total monopoly in the industry. They hold huge amounts of diamonds in storage meaning they can create shortages that keep prices high.

So ideally, when diamond prices skyrocket, the price of colored gemstones that are considered worthy alternatives also increases. When diamond prices stabilize, consumers prefer to purchase diamonds. Such is the diamond market.

Learn the Different Types of Diamonds

As mentioned earlier, diamonds are extremely pure – but deep down in the atomic level, they contain minor impurities in varied proportions that give gemologists a way of classifying them.

In general, diamonds are broadly divided into types I and II based on nitrogen impurities, and subdivided further according to the arrangement of nitrogen atoms and the occurrence of boron impurities.

Type 1 Diamonds

Type 1 Diamonds contain nitrogen and make up 98% of all diamonds.

And actually, that percent is specifically due to Type 1a diamonds. They absorb blue light making them everything from colorless to pale yellow and all the way to brown. Type 1b diamonds, on the other hand, have nitrogen atoms evenly spread out and they absorb both blue and green light. Their colors range from deep yellow, orange, brown and greenish. Less than 0.1% diamonds belong to type 1b.

Type 2 Diamonds

Type 2 Diamonds contain negligible amounts of nitrogen.

Type 2a diamonds are actually very ‘pure’ and usually colorless. Some structural anomalies allow them to absorb some light making them yellow, brown, pink, purple, or red in color. This type belongs to 1-2% of all diamonds. Type 2b diamonds differ from 2a because they contain boron instead of nitrogen. So they absorb red, orange and yellow light which gives them a blue color – although they can also be grey or colorless. This particular type makes up about 0.1% of all diamonds.

Synthetic diamonds

They look like diamonds, they shine like diamonds but they are not diamonds – at least not in the true sense of the word as we use it.

Synthetic or lab-grown diamonds are not a new phenomenon. Diamond growing began in the 1950’s. It was, and still is, mainly rooted in industrial production. And they are perfect for this because they embody all the necessary diamond traits without being as expensive as their natural counterparts.

Recent technological advancements have made the production process of lab-grown diamonds easier and much cheaper. And this has pushed some producers into the gem trade.

Lab-growing of type IIa/b HPHT (high-pressure, high-temperature) diamonds only hit the market as recently as 2014, according to GIA.

Learn to Differentiate Natural vs. Synthetic Diamonds

It’s impossible for an eye to tell if a diamond is natural or lab-grown, not even a jeweler, it needs advanced technologies and tools to find out that.

When choosing between natural and synthetic diamonds, the main difference will be evident in the price as it is related to quality. Since synthetic diamonds are created in labs, they are generally flawless and have ‘perfect’ attributes. Natural diamonds of a similar quality will generally be of a much higher price.

You should ALWAYS ask for the diamond certificate, and it should be a certificate from well-reputed labs (GIA, AGS, IGI), on the certificate it will be clearly indicated if that diamond is natural or lab-grown.

Generally-speaking, you should NOT be purchasing a diamond from a place that you might have 1% doubt they are selling synthetic diamonds as they are natural, always go for trusted stores like James Allen & Blue Nile for diamond shopping.

Ethics & Avoiding Conflict Diamonds

Conflict diamonds, also known as blood diamonds are those sold in order to fund armed conflict and wars. Profits from the trade of these diamonds has been used by warlords and rebels to fund terrible wars in Angola, DRC (Democratic Republic of Congo) and Sierra Leone. These wars are estimated to have cost over 3.5 million lives.


Though the wars in Angola and Sierra Leone are over and the war in DRC has decreased, conflict diamonds are still a concern. Especially since 65% of the world’s diamonds come from Africa. And some rebel-held areas in African countries still smuggle conflict diamonds through neighboring countries.

One way that was introduced in 2003 to curb the flow of conflict diamonds is the Kimberley Process Certification Scheme (KPCS).

It requires diamond industry participants to certify that their shipments of rough diamonds are conflict-free. With 80 countries having signed on, KPCS ensures that conflict diamonds stay out of the supply chain by isolating non-participatory countries from the global diamond market.

Support of the Kimberley Process and the Clean Diamond Trade Act is not just a role left to diamond industry professionals.

You as a buyer can also ensure that the diamonds you buy are conflict-free by scrutinizing the policies implemented by your local jeweler. Check whether there is a guarantee that their diamonds are sourced from Kimberley Process compliant importers.

Generally-speaking, all large retailors & major online stores are safe on this front, so when you shop from these known brands like James Allen or Blue Nile, it’s safe to assume you’re getting a conflict-free diamond.

Colored Diamonds

Diamond colors deserve separate mention because some colors are not accounted for in the diamond type classifications. Fancy color diamonds can be found in any color you can imagine.

Yellow and brown diamonds are the most common of the fancies and the most affordable out of all of them. They are followed by the rarer pinks and blues. The rarest ones are red, orange, green and purple diamonds.


Here’s what you need to know:

White Diamonds

They are the ones best known particularly due to them being an obvious choice for wedding and engagement jewelry. They are found in mines across the globe in different shapes and sizes.

Pink Diamonds

Only 1% of all diamonds have a pink color and so they are the rarest and most expensive of all. They represent beauty and romance making them perfect for romantic gifts.

Blue Diamonds

These are also extremely rare and expensive meaning most jewelers can only dream of owning one. Fancy blue diamonds exist in a variety of shades.

Green Diamonds

Another color extremely rare in diamonds is green. Such diamonds are bombarded by nuclear rays during their growth. The bombardment makes them absorb magenta wavelengths which in turn gives them a green color. They represent hope, nature and growth.

Yellow Diamonds

These diamonds are also called canary diamonds. The richer the yellow color, the more expensive the diamond becomes.

Orange Diamonds

These come in various tones and they represent success and creativity.

Purple Diamonds

Purple is associated with royalty making these diamonds perfect for the ultimate romantic gifts.

Champagne Diamonds

These are naturally colored and range from straw and cognac colors.

Brown Diamonds

They are the most common fancy colored diamonds. The terms “Champagne”, “Cognac” and “Coffee” are used to refer to different types of brown diamonds.

Buying Loose Diamonds vs. Diamond Jewelry

Loose diamonds are the kind that are not mounted on any piece of jewelry.

Buying a loose diamonds is something you may want to do if you want to create jewelry that has never existed before. It is also something you may want to do if you want the recipient of the jewelry to treasure it and flaunt it for years of end.

It might also be that you found a great loose diamond at a great deal, but you haven’t made sure what setting you want to put it on, and at the same time you don’t want to lose the deal, so you get the diamond then mount it on a setting once you make up your mind.

The buying process can be much easier if you already know your preferred diamond shape and then narrow down your options with the 4Cs.

Select your preferred diamond shape and narrow down your options by factors such as carat, color, clarity, and certificate or by budget.

There are a couple reasons why many people are now choosing to go the loose diamond route.

It is likely they know something you may not already know about loose diamonds, let’s see:

They are cheaper

Loose diamonds that are not mounted on any other material come cheap. Their affordability is also due to the fact that they are sold in wholesale. The additional costs of materials and manpower required to assemble diamond pieces is something that loose diamonds bypass.

They are flexible

Loose diamonds give you more control over the end product because you get to inject your own creativity and personal touch. With them, you can personalize a gift for a loved one in your own style instead of settling for predetermined designs based on someone else’s taste.

Loose diamonds are ideal for wedding and engagement rings where people prefer customization. They also save on a lot of ‘search time’.

Loose diamonds can also be set on various other forms of jewelry like earrings, necklaces, nose rings and bracelets.

How much more flexible could they get, really?

They are varied

Many shapes are available for a customer to choose from. Example of cuts available are pear, emerald, heart shaped, and round. This gives you an avenue to choose from a wide range of cuts.

They can be scrutinized

Mounting covers a sizable amount of a diamond hence the buyer is unable to tell if the diamond has faults or not.

Setting a diamond on other materials can definitely hide imperfections and you as the buyer might end up buying a diamond that is of less value than the amount of money you offered for it.

Something to remember however is…

If you are looking for top-quality – which should obviously be the case – then you must ensure that you get loose diamonds that are certified. They will cost a bit more than their non-certified counterparts but you will be able to rest easy knowing they are the real deal.

Diamond certification will be covered in a later section.

Not Breaking the Bank – Diamond Pricing & Your Budget

The key concern when it comes to buying diamonds is usually – price.

When shopping for diamonds, you need to understand how diamonds are priced in order to avoid going over budget or getting ripped off.

In general, diamond pricing is impacted by four key things: good-old supply and demand, the 4Cs of diamond quality, the shape of the diamond and grading.

Supply and demand points to the simple fact that availability and rarity drive prices higher or lower. As mentioned earlier, fancy colored diamonds which make up a small percent of the world’s diamonds are the most expensive.

That’s a given. Then you have quality, shape and grading.

These three need to be understood in a bit more detail in order to make your price research much easier before your next purchase.

Diamond Quality and Price

The 4Cs dramatically affect the price of any particular diamond.

Clarity and color increase and decrease the price of a diamond according to factors we already discussed earlier in the guide. Refer to the 4Cs and the Diamond Colors sections.

Carat and Cut, on the other hand, affect a diamond’s price in ways we did not really touch on earlier.

Carat weight is a key factor that affects diamond pricing. Diamond prices shot up exponentially as you move up in carat weight. As explained in the 4Cs’ section, the cost of a diamond is calculated on a ‘price per carat’ basis.

Keep in mind, not every carat is priced the same, the larger the carat, the rarer the diamond, and thus, the more expensive it would be, which takes us again to availability and demand.

The most widely used price sheets used in the industry are from Rapaport and IDEXA while back, they used to be accessible only to industry insiders- but today, you too can get access. You can do this by purchasing the updated price list (weekly) at a one-off cost of $50.00 if you find it necessary.

Something you need to note however is that depending to a diamond’s specific characteristics, its price can go significantly higher or lower than the official Rapa value.

So another trusted way to do some serious price research is by visiting online diamond retailer listings. Sites like Blue Nile, James Allen and Whiteflash could give you access to price information of rough diamonds with your chosen specifications.

A key thing to remember, however, is that you cannot do blind comparisons. We cannot be any clearer with this. Eliminate as many differentiators as possible in order to make fair comparisons. The 4Cs of diamonds you select should carry the same qualities.

Cut also affects price in a big way.

Cut is the best value quality since it determines a diamond’s beauty more than any of the other factors. And why would everyone covet diamonds if not for their beauty?

Note, however, that diamond cut in relation to price usually carries two meanings: cut quality and cut shape. Both cut quality (proportions, symmetry and polish) and cut shape (e.g. round, oval, pear, etc) are key factors to consider when doing price research.

Cut quality is achieved when the cutter manages to balance a diamond’s optimal cut (and appearance) against its maximum yield. Maximum yield here refers to a result where the cutting maintains as much carat weight from the rough diamond as possible.

But the problem here is usually that customers prefer to sacrifice cut quality for size. And this in turn puts pressure on the cutter to sacrifice appearance for weight. So Cut grade is important to allow you, as the buyer, to determine whether a diamond’s fair to poor cut was ‘intentional’ in order to gain some carat weight.

Diamond Shape and Price

Cut shape is another thing to keep in mind when shopping for that perfect stone. Something you need to remember is that round shaped diamonds usually cost more than other shapes of diamonds.

Round diamonds cost more due to very high demand and their relatively low yield. The low yield is due to much of the rough diamond being lost during cutting which means whatever is left over is of a higher cost per carat.

Round diamonds make up approximately 75% of all diamonds sold. The mechanics of a round shape enhance the reflection of light therefore making these diamonds pretty-much perfect in their fire and brilliance.

Diamond Grading and Price

Diamond grading also affects price. Grading is done in one of these three prominent gem labs: GIA, AGS and IGI, with GIA being the highest reputable lab globally.

As expected, they grade diamonds differently and this is reflected in the price.

So when comparing diamonds, make sure you are looking at suppliers who use the same grading labs, and also make sure you don’t get diamonds that are graded by less reliable labs like EGL.

How to Choose the Perfect Diamond and Jewelry Setting

The hardest part about shopping for diamonds is not necessarily in finding the ring one for your budget. It is more in just finding the right one. This is because once you do all the due diligence and figure out a budget you want to work with, there is still a wide array of diamonds you could choose –which is usually the kicker.

By keeping a few things in mind, you can make the entire process much easier.

Keep in mind that it is easier to select loose diamonds than it is to select diamond jewelry.

With the latter you need to consider the setting type and metal type over and above knowing which quality of stone you want to get.

With these few guidelines up your sleeve, diamond shopping can only get easier.

Selecting the Shape of the Stone

Selecting a diamond’s shape is probably the most important part of the buying process. Right up there with selection of color.

It is also the one aspect of diamond buying that should take into consideration the taste of the person receiving the gift if that is the reason for the purchase. The purchaser could decide on the price and quality of a diamond but its shape should be tied to what the receiver wants.

Diamond cutters over the years have pushed the boundaries by introducing shapes outside the scope of what the industry is used to. And this means shape selection has become a bit more complicated.

Selecting the Setting type

Setting type is mostly associated with rings.

When you are buying a diamond ring, there a various setting types that you can keep in mind when selecting your chosen piece.




And it will not just be about your choice. You will need to keep the recipient’s lifestyle in mind. Consider how their normal day looks like and what hobbies they engage in. Consider their taste as well, what styles they like to follow, etc.

The Setting you choose should also be determined by the ring’s meaning, current trends and of course your budget.

Selecting the Metal type

Metal type is usually the most downplayed factor in ring selection. This is usually because most people have absolutely no information about why they should prefer one metal over another.

Metal choice, like setting type, should depend on your budget and lifestyle – more importantly on the kind of wear and tear the ring is likely to go through.

So no more guesswork when you are out ring shopping. Here are some tips you should keep in mind:

  • Platinum: Platinum is a timeless option for both men and women. It is 30 times rarer than gold which makes it more expensive. It is also 40% heavier than 14K gold and its hardness means engravings look better on it. It is a natural gray metal and will form a patina as it ages. Platinum is “forever white”.
  • Palladium: Palladium is from the platinum group of metals though it is more affordable. It is 15 times rarer than platinum making it the rarest of the six in the platinum group. It is naturally white, durable, lightweight and resistant to discoloration. It doesn’t require alloys or plating meaning it is usually 95% pure.
  • Sterling Silver: Silver is a metal that has been valued for centuries on end. At one point it was even more valuable than gold. Today is one of the most affordable precious metals. Sterling silver is pure silver mixed with copper and other metals to make it more durable since pure silver is much too ‘soft’. Due to tarnishing, ensure to store your silver jewelry in tarnish-preventable bags.
  • Gold: Gold is the most traditional of all wedding band metal choices. It’s a malleable metal and can be reshaped, polished, stretched and sized throughout its life. Pure gold is too soft to be used in jewelry and that is why it is usually mixed with other metals. The alloy mixed with gold affects its color. The exact color to select will be a matter of preference.
  • Yellow Gold – This is pure gold mixed with some silver and copper for a brighter look.
  • White Gold– This is pure gold mixed with palladium and silver or with nickel, copper and zinc.
  • Green Gold – This is pure gold mixed with silver giving it a yellowish-gold appearance.
  • Pink and Rose Gold – These are made with a mix of pure gold and copper. The more the copper the ‘redder’ the result.
  • Tungsten Carbide: Tungsten carbide is an extremely hard and scratch-resistant metal. It makes an excellent option for the handyman recipient. Its dark gray heavy look makes it an exceptional choice for stylish rings. Rings made with it cannot be sized.
  • Tantalum: Tantalum is a rare, dense, blue-gray colored hypoallergenic metal. It is a great alternative to gold or platinum. It can be stretched or condensed up to a half-size. Unlike other metals, it’s shatterproof, biocompatible and economical.
  • Titanium: Titanium is a lustrous transition metal with a low density. It’s popularly used for men’s wedding bands. It is of high strength and is extremely economical. Rings made with it are NOT malleable but they will be fairly scratch-resistant.
  • Cobalt Chrome: Cobalt chrome is an alloy of cobalt and chromium. With a strong white metal look and the closest match to white gold, it’s strong, highly resistant and biocompatible. Its rings cannot be sized, nor stretched, but they can stand the test of time.
  • Stainless Steel: Forget cutlery- stainless steel is perfect for jewelry too. It is popular for its strength and affordability. Whether chosen in a matte look of pewter or the reflective look of chrome, people appreciate the general sturdy, modern look.

Ring Sizing

Okay, so you may have gotten all the above right when selecting your diamond piece. Now all you need to do is get the correct size. This is hardly an issue with other jewelry types.

But it is especially important when talking engagement and wedding rings. These are pieces that are worn for years on end and they need to be perfect.

Engagement rings are a special case since they are usually bought without the recipient present. And this means their sizing has to be exact because getting it wrong does not only disappoint your loved one, it also means coughing up more money for resizing, and in some cases, resizing won’t be a good option if ring size is too large.

You can prevent all this by using a ring sizer. There are various printable ring sizers online.

Avoiding Diamond Scams

Diamond certification or grading is a topic of great importance because it largely affects the price you will pay for any loose diamond or diamond piece. So the one thing you will need to learn, after understanding the basics of certification, is how to read a diamond grading certificate. This section will help you with that.


A diamond is usually thoroughly scrutinized using trained eyes, a jeweler’s loupe, a microscope, and other industry tools. Once all that is done, gemologists issue a report in the form of a certificate.

A completed certificate should include an analysis of the diamond’s dimensions, clarity, color, polish, symmetry, and other characteristics.

One thing you must remember though is that lab certification is not an appraisal. An appraisal usually focuses on the value of the diamond, mainly for insurance purposes. A certificate doesn’t determine a diamond’s market value. It determines its characteristics and quality.

Labs that command the highest premiums for grading reports are: The Gemological Institute of America (GIA), American Gem Society (AGS), and Gem Certification and Assurance Lab (GCAL).

In terms of certification standards, these labs operate quite differently from each other. Some of the differences are driven by profit. An example, GIA is a non-profit organization while IGI is a commercial organization.

IGI could choose to grade a diamond an average of one point higher than those given by GIA and AGS to keep their buyers eager and happy. So for a buyer looking at two similar diamonds with grades from IGI and GIA respectively, it can be hard to know what you are actually paying for.

A lower grade with GIA would mean a lower price. A higher grade with IGI would mean a fair price – hence you would compromise on quality if the price attracts you.

As a buyer, you should never underestimate the issue of diamond certification. It all comes from a wide range of labs, all with varying strengths and weaknesses. But in order to get the best buyers’ deal, you should count on buying diamonds that have either GIA or AGS certification.

Diamond Certification

GIA is short for The Gemological Institute of America. It is the world’s oldest, largest and most respected independent laboratories in the world. Unlike other labs, GIA is not owned or partially owned by diamond industry insiders. This means that its certification and grading efforts are quite objective.

Retailers who sell diamonds graded by GIA usually accompany each of their diamonds with a GIA Grading Report or Dossier. These can be checked prior to purchasing online if the retailer is an online store.

GIA Certified Loose Diamonds

A GIA Dossier is similar to the Grading report but the only difference is that it is more condensed and suitable for smaller diamonds.

A GIA diamond grading report usually included the following:

  • Shape and Cutting Style
  • Measurements – in millimeters
  • Carat Weight – to the nearest hundredth of a carat
  • Color Grade – assesses the absence of color in a diamond
  • Clarity Grade – determined under 10X magnification
  • Cut Grade – determined by a diamond’s appearance, design and workmanship
  • Finish
  • Polish
  • Symmetry
  • Fluorescence – Color and strength of color under UV light.
  • Comments – diamond characteristics no already mentioned in the report.
  • Clarity Plot – the size, type and position of inclusions as seen by the microscope
  • Proportion Diagram – the diamond’s actual proportions

The Best Places to Buy Diamonds

Check out our full James Allen Review and Blue Nile Review

Whether you are buying diamonds at a physical store or online, there are a couple of questions you need to ask first before making your purchase with your chosen retailer.

  • How long have they been in business?
  • What kind of reviews have they received?
  • Do they assure secure transactions?
  • Do they belong to a jewelry trade association to hold them ethically accountable?
  • What is their current return policy?
  • Is their staff helpful?
  • Where are they located?
  • How will the diamond be shipped? Will a signature be needed on delivery? Is the shipment insured?
  • If an online retailer, is there sufficient evidence of the diamond quality? In form of reviews, photographs, grading reports?

Diamond Insurance and Appraisals

Like with other high-value possessions, insurance is always a great idea. Home insurance policies normally cover theft of jewelry but not really damage or loss. So check your policies and try to get jewelry specific insurance to be on the same side.

Diamond appraisal is important to your insurance agents and also for jewelers you will go to for upgrades or for potential resale. There are several appraisal organizations that you can consider. In addition to supplemental appraisal training, appraisers should have a GIA Graduate Gemologist (GG) diploma.

Common Mistakes When Buying Diamonds

Buying diamonds can be a tricky affair if you are not conversant with how to buy diamonds correctly. There are some common mistakes that buyers makes and once you know them, your visit to the jeweler will be much easier next time you go.


First things first, most people are misled by cut quality. This is because it is harder to ‘see’ than the other 4Cs like color and clarity. It is also the quality that most jeweler play around with to get an extra buck.

To ensure that does not happen during your purchase, keep in mind a few things.

First, do a lot of research online and through window shopping in order to know what options you have before a jeweler presents you with their ‘best’ collection.

Secondly, be careful with deeply cut diamonds as they will have more carat weight without necessarily have more ‘diamond’ along the width, this image explains how a “too deep” diamond will have higher carat, but less light reflection:

Diamond cut and light reflection

Third, well cut diamonds cost more than fairly cut ones. So do not go for a bargain price if what you really want it a perfectly cut piece.

In a nutshell, ALWAYS aim to guarantee an ideal/excellent cut, then look for other characteristics.

Loose diamond vs. Set diamonds

It is really difficult to evaluate a diamond’s clarity and color once it is set on a jewelry piece. This is obviously because flaws can be hidden atop settings and metal pieces.

A key thing to remember is that you should not purchase diamond worth over $ 2,000 dollars without examining them as loose pieces before they are set.

Colors vs. Color ranges

Color is usually the kicker. GIA has done a lot to ensure there is a system in place. So do not accept the jeweler’s ‘grading’. Some use color ranges to further feign honesty. Do not fall for it.

Always compare the diamond on offer with the jeweler’s master color set. This is a standardized set of cubic zirconia stones that show various sets of color. Simply hold your diamond against the master color set and find out where yours stands on the spectrum.

Remember that cut quality can also affect the color of a diamond because it affects brightness. For round diamonds, use the GIA cut grade. For fancies, compare depth, table, symmetry and fluorescence of two diamonds before doing a color comparison.

Always remember that a jump from colorless to near colorless range costs higher than jumping within the same range, like in this image here, moving from G to F will cost you more than moving from H to G for example:



Keep in mind that a jewelry store’s lighting is designed to enhance the diamond’s color and make it look more attractive. Kindly request the jeweler to switch to normal lighting to enable you to make a wise and informed decision. You could also take the diamond outside the showroom area to a different room.

Carat weight

Carat weight is normally rounded off to the next figure so you should ask the jeweler about the exact weight. This will enable you to easily compare different diamonds.

Gemological Institute of America grading report

Every reputable jeweler should have a certificate from GIA. The certificate will allow you to know everything about a diamond that the jeweler might otherwise not disclose. Things like whether the diamond has been treated in some way to enhance its appearance or not. The certificate contains correct and accurate information to help you know exactly what you are buying.

Visit several online stores

Jewelers exist to make money and so they will always try to sell you the best they have in the store but not the best there is at the price they are offering.

Some shops come with great recommendations and referrals. Others have mastered the art of great advertising so they can easily be able to pull in a lot of customers.

Don’t be in a hurry. Simply shop around and do your homework. This way, you will be able to purchase only the best there is for your hard earned dollars.

Price Calculations

Diamonds don’t often come with a price tag and the jeweler normally quotes this for the buyer. It is wise to use a calculator to enable you determine discounts offered on the diamonds. From that you can be able to bargain and the jeweler can then lower the price accordingly.

Jewelers’ policies

Most jewelers have a set of policies in place for warranties and/or guarantees. Always ask to see them in writing before making any payments.

Confirm what is included in the warranty. Besides the standard free cleaning and inspections, is loss and theft covered? And remember that a warranty can never take the place of insurance.

How to Protect Your Diamonds and Diamond Jewelry

One way to protect your diamond is to be mindful of where and who you leave it with.

When leaving your diamond with a jeweler for some maintenance measures like cleaning and resizing, be sure to do these key things if you are afraid of a ‘switch’ being made:

The first thing you need to do is to take note of the GIA certificate number inscription. Share this with the jeweler for them to know you know it exists and so that it is not interfered with in maintenance activities.

In case you have a very expensive diamond, take it to an independent appraiser to evaluate it and put their findings in writing. After maintenance or repair, take the diamond back to the appraiser to check if it is in the same one or in the same condition they left it in.

Another way to protect your diamond is to take care of it.

Diamonds are often marketed as being indestructible – but they are not. They can be chipped by a strong blow, they could get loose from a weak setting or they could be damaged by other diamonds.

Be sure to store them in padded boxes and clean them with lint-free cloth or by dipping them in commercial cleaning solution. You could also just let your jeweler handle the cleaning if your take the precautions above when leaving your piece with them.

Information is power. It will always help you on the subject of how to buy diamonds correctly.


It’s really a pleasure for us that you’ve reached this point, whether you skimmed some parts, or went over the article intensively, it means a lot for us.

We hope that you have much better idea about your diamond purchase, what to look for, where, how to negotiate, and how to get the best bang for your buck.

Shall you have any questions? We’re always here to help, please drop us a message using the form below, and we will be glad to help, free of charge of course.

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About the author

Olivia Bennett is a dynamic and accomplished expert in the diamond industry. With over a decade of experience, she has established herself as a go-to authority for all things diamonds. Olivia's love affair with these exquisite gemstones began in her childhood and has only grown stronger over the years.

Having worked closely with diamond miners, manufacturers, and retailers, Olivia possesses a comprehensive understanding of every aspect of the industry. From diamond grading to sourcing and the latest design trends, her expertise is unparalleled. Clients value her impeccable taste, attention to detail, and personalized approach.

Driven by a passion for education and empowerment, Olivia launched her own website dedicated to diamonds. Through engaging and informative content, she guides individuals through the intricacies of diamond buying, helping them make confident and informed decisions.

Olivia's mission is to ensure that everyone finds their perfect diamond, one that truly reflects their unique desires. With her extensive knowledge and unwavering dedication, Olivia is a trusted guide in the dazzling world of diamonds.