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how  to pick the perfect diamond

The world of jewelry is a whirlwind of sparkle and color, but nothing makes a statement quite like the dazzle of a diamond. Whether you need a diamond for an engagement ring, a pendant or even multiple diamonds for a special piece of jewelry, it’s important to know what you’re getting. This little gem will be an important part of your life or the life of someone you love for many years to come – and if you play your cards right, a quality diamond can become a lifelong treasure. Before you purchase, take a look at our diamond-buying guide to help inform your decision.

Why Choose a Diamond?

It’s commonly known that a diamond is one of the most coveted gems – especially for engagement rings – but do you know why? Historically, the tradition of using diamonds for engagement jewelry is a fairly new one. In the late 1930s, the DeBeers company began a campaign to instill diamonds as markers of luxury in the minds of the nation. Celebrities of the time began to realize their elegance, and the populace were enticed by the idea that diamonds are forever.

Today, diamonds still represent the ultimate in romantic gestures, and they really can last forever if you know how to spot quality. The clarity and sparkle that made us fall in love with diamonds are the characteristics to look for in a quality diamond, and there are four distinct ways to judge this gem.

The Four Cs of Diamond Buying

Upon initial investigation, it can be hard to figure out how to choose a diamond, as well as determine which ones are iffy and which ones make the cut when it comes to quality. After all, they’re all relatively small and sparkly, so how can they be priced so disparately? It turns out, judging the quality of a diamond is actually more of a science than most people imagine. To get a good picture of where a diamond stands on the quality scale, take the four Cs of diamonds into consideration.

  1. Carat

    how  to pick the perfect diamond

Most people know that more carats are better, even if they aren’t sure what the word means. While that’s a pared-down simplification, it is true that carats are an important measure of diamonds because they quantify the diamond’s size and mass. A carat is a metric measurement that equals 200 mg, or one-fifth of a gram.

Because they’re such a small measurement, carats can also be subdivided into a 100-point scale, which allows for measurements down to the hundredth decimal place. In general, the price of diamonds increases proportionally to carat weight because larger diamonds are rarer. However, it’s important to note that two diamonds of the same weight can have vastly differing values due to variation in other factors of the four Cs.


The reason diamonds are so renowned is the way they can reflect and transmit light to create an intense sparkling effect. Since diamonds in the rough just look like slightly iridescent rocks, the way this is achieved is through the way the diamond is cut to create its shape and facets. The quality of the cut is both a measure of the stone itself and the craftsmanship of the jeweler, making it one of the hardest aspects to judge. Luckily, there are subcategories that can help you determine how to choose a diamond cut:

Brightness: The internal and external reflection of white light

Fire: How light disperses from white into every color of the rainbow

Scintillation: How much sparkle the diamond creates, and the evenness of light- and dark-area patterns

  1. Clarity

Natural diamonds are formed when carbon is exposed to extreme heat and pressure deep in the Earth for a long time. When that diamond is extracted and cut, one might be able to see some internal imperfections called inclusions, or external characteristics called blemishes. When evaluating a diamond’s clarity, jewelers look for the size, position and number of inclusions and blemishes, as well as how they affect the diamond’s overall appearance.

The Gemological Institute of America (GIA) scale of clarity grading contains six categories, some of which are subdivided into 11 distinct grades. All grades describe what can be seen at 10-times magnification.

Flawless (FL): No inclusions or blemishes visible

Internally Flawless (IF): No inclusions visible, though a blemish or two may exist

Very, Very Slightly Included (VVS1,VVS2): Inclusions small enough that a skilled grader has significant difficulty seeing them

Very Slightly Included (VS1, VS2): Inclusions are observed with some difficulty, but can be considered minor

Slightly Included (SI1, SI2): Inclusions are noticeable

Included (I1, I2, I3): Inclusions are obvious, and may affect the transparency of the diamond as well as its brilliance

  1. Color

The color quality of a diamond is based on how little color it has. A perfect diamond would be completely colorless. The GIA color scale ranges from D for colorless diamonds to Z for diamonds with an obvious yellow or brown hue. It might be difficult to tell the difference between a G diamond and an H diamond, but the difference between a D grade and S grade would be obvious. Color distinction can make a big difference in the value and quality of a diamond.

As you may have noticed, many of these quality markers need to be seen under magnification – and even then, they’re often only visible to a trained eye. Luckily, you don’t need an eagle eye to judge diamonds yourself because any reputable jeweler will happily provide the grading specifications of any diamond that interests you. Thom Duma Fine Jewelers even offers an an online diamond search tool that allows you to browse diamonds of your preferred carat, cut, clarity and color so you can find the exact balance of characteristics for your budget before you even step foot in the store.

How to Choose a Diamond Shape

Picking the perfect diamond isn’t just about the quality of the substance, it’s also about the style. Now that you have an idea of how to pick a diamond cut for quality, it’s time to turn your eye to what shape you or your intended recipient like best. Most diamonds on the market are brilliant-cut, which just means that most of the facets are triangle or kite-shaped and radiate outward from the center of the stone. Here are some of the most popular shapes you’re likely to encounter on your mission to pick the perfect diamond.

  • Round Cut

    how  to pick the perfect diamond

By far the best-selling diamond out there, the round-cut diamond makes up about 75 percent of the world’s market – and for good reason. It’s possibly the most cost-effective diamond cut for the brilliance because of its usually uniform facets.

It’s almost impossible to go wrong with a round cut due to its symmetry and shape. The original specifications for the perfect round-cut diamond were created in 1919 by Marcel Tolkowski. His work explained the perfect proportions for bringing out the most brilliance and fire in the diamond, and we’ve been making small modifications ever since. Today’s round-cut diamonds are more brilliant and scintillating than ever, thanks to the introduction of lasers and other modern technology into the diamond-cutting world.

  • Princess Cut

    how  to pick the perfect diamond

This exceedingly popular fancy diamond is a square cut, created in the 1960s. It has a hidden advantage in its four corners: Keeping the square shape means that about 80 percent of the rough diamond is retained, as opposed to the 50 percent maintained in a round cut. That means the diamond ends up slightly cheaper by weight.

The ideal princess-cut diamond is an exact square, but many are actually slightly rectangular – and therefore lower in price. This can translate into a bargain for many buyers, because any rectangularity may be hardly noticeable, or easily masked with proper mounting. Princess-cut diamonds are so popular in part because of their ability to work with practically any setting.

  • Marquise Cut

The Marquise-cut diamond is a modification of the brilliant cut that results in an oblong, football-shaped diamond. By carat weight, the marquise cut has one of the largest surface areas of any diamond shape. That means it’s a great option if you’re interested in maximizing the perceived size of your diamond.

The stones also come with a rather romantic history. It’s said that King Louis XIV of France had a diamond specially crafted to resemble the perfectly proportioned mouth of one woman: The Marquise of Pompadour. The classic length to width ratio is 1.75 to 2.15, though only your preference can dictate whether you choose a narrower or wider diamond.

  • Emerald Cut

These diamonds have a unique look thanks to their step-shaped cuts and large, flat face. In contrast to the sparkle of brilliant-cut diamonds, emerald cuts produce an effect that’s more like looking down a hall of mirrors. It is a very elegant cut that catches the eye much differently than a classic round cut would, but the flat surface makes any inclusions stand out more than other cuts.

Color evaluation of these diamonds is quite subjective. When the diamond contains more flat surfaces, having a slightly warmer tone can be easier on the eyes than the coolness of a colorless diamond. As for proportions, there is no ideal. Emerald cuts range from square to rectangle with personal preference governing your choice.

  • Cushion Cut

This diamond variation takes the square cut of the emerald and pairs it with rounded edges, producing the pillow-like appearance that gives the cut its name. This cut is more than 200 years old, and for the first half of that time it enjoyed popularity on par with that of brilliant round-cut diamonds today. Until the 20 th century, cushion cut was the default diamond shape.

The classical cushion cut is a square, but other ratios are acceptable as well. Elongated cushion-cut diamonds can look stunning in pendant, earring and ring settings alike, so don’t spend too much time worrying over the technical specs of your cushion cut shape.

  • Heart-Shaped Cut

Nothing says love like a heart-shaped diamond cut. This unmistakable iteration of the brilliant cut is most popular in rings and pendants. It may be unwise to choose a heart-shaped cut if the diamond is less than .50 carats. The heart shape can be hard to distinguish in smaller diamonds, and setting the stone in prongs makes it even more difficult.

The diamond should be large enough to identify the heart shape, as well as symmetrical. They can come in a range of silhouettes, from narrow to wide. Though the standard length to width ratio for these diamonds is 1 to 1, personal preference and the diamond setting will make the difference in choice. For example, a longer, narrower heart-shaped diamond may look better on a pendant than on a ring, and a wider diamond might enhance a ring setting.    

Where to Purchase the Perfect Diamond

how  to pick the perfect diamond

Now that you know the basics of how to choose a diamond, you should feel significantly more confident in your ability to find the perfect one for your needs. That doesn’t mean you should run out and hand your money over to the first jeweler or online vendor you find. Your diamond should be a treasure for life, so it’s important to find a jeweler that will treat it as such. Thom Duma Fine Jewelers has been crafting quality jewelry for more than 33 years, and we know diamonds. There are three simple reasons you should choose Thom Duma for your next diamond purchase:


  1. Free Financing

Buying a diamond is a big deal, but you don’t have to break the bank to do it. Take advantage of the TDFJ Private Credit Card, with terms up to 12 months. That’s up to one year to pay off your diamond with zero interest and zero fees.

  1. In-Store and Online

Online-only jewelry retailers can seem like a great bargain, but they’re more often traps for the novice diamond-buyer. Not only do they offer little to no customer service during the ring-buying process, there is no guarantee they’ll be there to help you if anything goes wrong with your ring. There’s also the matter of quality – how do you know what you’re getting if you will never have the opportunity to see the diamond in person before you buy it?

Thom Duma Fine Jewelers takes pride in being a rounded retailer, with the convenience of online browsing, searching and education, and the expertise of real, qualified individuals. You can even consult with the design team to create a unique masterpiece. Don’t settle for sight-unseen diamonds when you can receive step-by-step guidance in the selection process.

  1. Lifetime Diamond Warranty

Thom Duma Fine Jewelers doesn’t just provide support during your purchase, but for the entire life of the diamond. Every single diamond engagement ring and wedding band purchased from Thom Duma Fine Jewelers comes with a free lifetime warranty. That includes free replacement of cracked, chipped or separated diamonds, as well as free cleaning, sizing, soldering, repairs and more.

Thom Duma Fine Jewelers is the premier destination for all your diamond-buying needs. Don’t hesitate to stop by the store for a consult, call or email us to find out what we can do for you.