Diamond Buying Guide

Diamond Guide

Choosing the right diamond requires knowledge and understanding of a diamond’s unique properties and qualities. We offer our customers an extensive educational section devoted to the “4C’s” of diamond quality – as well as the fascinating history and journey of diamonds from mine to retail.


The Four C’s!


Know your carats

Carat weight is one of the “4 C’s” used to evaluate diamonds and is therefore one of the most important factors in determining the price of a diamond. The term is derived from the carob seeds, which were used to balance scales in ancient times because of their uniformity of weight and shape.

The carat system is used to express the weight of a diamond and many other gemstones. One carat equals approximately 200 milligrams (0.2 grams). There are 142 carats to an ounce. Carats are also divided into “points,” with one carat equaling 100 points.

Please note that “Carats” are different than “Karats.” Whereas the term “carat” refers to the system for weighing diamonds, the term “karat” refers to the system for measuring the purity of gold.

How Different Carat Weights “Measure Up”

When it comes to jewelry, carat weight is extremely important because it determines the size and appearance of your ring, earrings, and other pieces. The tool below illustrates what diamonds of various sizes look like set in jewelry and how these different sizes look in comparison to one another. Please note that differences in diamond sizes will not always seem in proportion to the naked eye; a 2-carat diamond doesn’t appear to be twice as large as a one carat diamond.

Please Note: Each earring represents half of the total carat weight. For instance, in a pair of 1-carat total weight diamond earrings, each earring holds a stone of 0.50 ct.

Carat Weight Drives Diamond Prices

Diamonds are formed under very rare circumstances, are often very difficult to mine, and are usually found in relatively small quantities. This is one of the main reasons why they are so valuable. In most cases, larger sized diamonds are rarer still, making them worth significantly more than smaller sized diamonds in most cases. For instance, a 2-carat diamond is always worth more than two 1-carat diamonds of equal or similar quality. Likewise, a 1-carat diamond will cost much more than a 95 pointer (0.95 carats) of equal or similar quality – even though the two stones are very close in size. In general, the larger the diamond, the higher the price.

Exceptions to this rule would be when other diamond factors such as clarity, color, and cut come into play. These factors can have a significant impact on the price of a diamond – for instance, it is entirely possible for a smaller stone of exceptional quality to be worth more than a larger stone of only average quality.

The most difficult challenge for any diamond cutter is to preserve the greatest possible weight from the original rough diamond and still produce a finished stone with the best possible quality in terms of clarity, color, and cut.

How To Choose The Right Weight

There are a number of factors to consider when deciding what size diamond to purchase, including quality, style, body type, setting, and budget.

If you prefer larger diamond styles but have a limited budget, you can get a bigger diamond by looking a little further down the quality scale on clarity, color, or cut.

Keep in mind that the smaller the person, the larger the diamond will appear, and vice versa. A 1-carat diamond ring or stud earring will not look the same on a larger wearer as it would on a smaller wearer.

The setting style can also be very important, particularly if you are trying to match a loose diamond to a setting. Make sure the setting you choose is made to fit the carat weight of your diamond.

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Why Is Cut Important?

As one of the “4C’s” of judging diamond quality, cut is extremely important in determining a diamond’s value and price. Yet it is probably the least understood of the “4C’s.” So what exactly is “cut?”

Cut refers to the skill of the diamond cutter in unlocking the full beauty of a diamond during the cutting and polishing process. While nature determines the clarity and color of a diamond, man-made factors like cut influence a diamond’s quality and value. Even if a diamond has exceptional color and clarity, a poor cut will cause it to lose sparkle and fire.

When evaluating cut, a number of factors are considered, including the execution of the diamond’s overall design, the skill with which it was cut, the quality of its polish, its roundness, depth, width, and the uniformity of its facets.

A diamond is cut according to an exact mathematical formula. The most common cut, the round brilliant, has 58 facets – small, flat, polished planes designed to yield the maximum amount of light to be reflected back to the viewer. This reflection, known as brilliance, gives a diamond its unparalleled sparkle and fire.

A diamond’s proportions – particularly its depth compared to its diameter, and the diameter of the table (the largest and topmost facet of the diamond) determine how well light will travel within the diamond and back to the eye.

A well-cut diamond has the right angles and proportions to release the inner brilliance of the stone and project its maximum sparkle and fire. A poorly cut diamond – one that is cut too deep or too shallow – loses light and becomes a “dull” diamond that may even have some “dead” spots inside.

The Cut

Two keys to a diamond’s brilliance are its crown and pavilion. The crown is the top portion of a diamond extending from the girdle (the outermost edge of a cut gem) to the table. The pavilion is the part of the diamond below the girdle. Above the girdle of a round brilliant cut diamond are 32 facets plus the table. Below the girdle are 24 facets plus the culet, or point. Just a few degrees off the standard can have a dramatic impact on a diamond’s brilliance. However, cutters can compensate by adjusting crown angles, table sizes, and pavilion angles to produce the best possible results for each diamond.

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The Importance Of Diamond Color

Although most diamonds may appear to be colorless to the untrained eye, truly colorless diamonds are extremely rare and highly prized. Color can hinder the passage of light through a diamond, lessening its spectacular sparkle and fire. Even a slight tinge of yellow or brown can have a dramatic impact on a diamond’s value. Determining the presence or absence of “color” in a white diamond is one of the famous “4 C’s,” or key indicators, of a diamond’s quality. In general, the whiter the stone, the greater its value.

Most diamonds are graded on a professional color scale that begins with “D” for colorless and continues all the way down to “Z”, with a stone’s yellow or brown tint becoming increasingly visible as you move down the scale.

D: Absolutely colorless – The highest color grade, which is extremely rare.
E: Colorless – Minimal traces of color that can only be detected by an expert gemologist. Also a very rare diamond.
F: Colorless – Slight color, which can only be detected by an expert gemologist, but is still, considered a “colorless” grade. A high quality diamond.
G-I: Near colorless – Color noticeable when compared to diamonds of better grades, but these grades offer excellent value.
J-K: Near colorless – Color slightly detectable. An excellent value The color of these diamonds gives them a slightly noticeable tint to the naked eye when compared to diamonds of better color grades.
L-M: Slightly Colored – Color slightly detectable. An excellent value The color of these diamonds gives them a slightly noticeable tint to the naked eye when compared to diamonds of better color grades.
N-Z – Lowest quality normally not sold for jewelry.

Which Color Should I Choose?

Diamonds further down the color scale can still be very beautiful, appear colorless, and display impressive sparkle and fire with the proper cut, high clarity, and in the right jewelry setting. Diamonds with lower color grades also represent a significant dollar value over stones with little or no hint of color. In fact, many people actually prefer the warmer glow of diamonds with lower color grades. Most people buy a diamond with the best color grade they can afford while taking into account the other “3 C’s” of diamond quality: carat weight, clarity, and cut.

A Word on Fluorescence

Fluorescence is the reaction of some diamonds exposed to UV lighting. Fluorescence makes some clear diamonds appear to be cloudy and some yellow tinted diamonds appear to be clear under UV lighting. Under normal lighting conditions, fluorescence is not detectable. Even trained gemologists are unable to consistently agree on the effects of fluorescence. Therefore, whether or not a diamond displays fluorescence is of only minor importance in the purchasing decisions of most diamond buyers.

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The Importance Of Diamond Clarity

Clarity is one of the key indicators of a diamond’s quality – and therefore, its value. Clarity is so important, it is one of the “4C’s” used to evaluate a diamond. Clarity refers to the presence of a surface or internal marks, also called flaws, within a diamond caused during its formation deep in the earth or during the cutting process.
When these marks occur on the surface of the diamond, they are known as blemishes. When they occur internally, they are called inclusions. These flaws can take the form of scratches, chips, cavities, stress lines or fractures, crystals or bubbles within the diamond, and other imperfections.

All diamonds have flaws. Because no two diamonds have the same flaws, these marks provide each diamond with a unique “fingerprint” that gemologists can use to identify it.

Blemishes and inclusions can interfere with the passage of light through a diamond, diminishing its beautiful sparkle and fire. In the rarest and most expensive diamonds, these marks are too tiny to see even under magnification. The general rule of clarity grading is: the fewer (and smaller) the blemishes and inclusions, the rarer and more valuable the diamond.

How Are Diamonds Graded For Clarity?

Diamonds are graded for clarity by trained gemologists under a loupe at 10x magnification. Clarity grades are based on the size, number, and position of imperfections in a diamond. Diamonds that appear to be completely free of any surface or internal flaws under 10x magnification receive the highest clarity grades of “Flawless” (FL) or “Internally Flawless” (IF) according to the Gemological Institute of America’s (GIA) clarity grading scale. At the other end of the spectrum, diamonds with large and/or numerous blemishes and inclusions visible to the naked eye fall under one of the “Included” grades (I1, I2 or I3) under the GIA clarity grading scale.

FL (Flawless) – No surface blemishes or internal inclusions visible to a trained eye under 10x magnification. An exceptionally rare, beautiful, and highly valuable diamond.
IF (Internally Flawless) – No internal inclusions and only very minor surface blemishes visible to a trained eye under 10x magnification. A very rare, beautiful, and highly valuable diamond.
VVS1 – VVS2 (Very Very Slightly Included) – Few, very tiny inclusions and/or surface blemishes difficult for a trained eye to see under 10x magnification. An excellent quality, beautiful diamond
VS1 – VS2 (Very Slightly Included) – Very small inclusions and/or surface blemishes only visible to a trained eye under 10x magnification. High quality, beautiful diamonds.
SI1 – SI2 (Slightly Included) – Small inclusions and/or surface blemishes are easily seen under 10x magnification, but very difficult to see with the naked eye. A beautiful, good quality diamond.
I1 (Included 1) – Inclusions and/or surface blemishes are easily visible under 10x magnification, and usually visible to the naked eye. Little effect on a diamond’s brilliance
I2 (Included 2) – More and larger inclusions and/or surface blemishes are visible to the naked eye. Some diminished brilliance to the diamond.
I3 (Included 3) – Many very large inclusions and/or surface blemishes are easily visible to the naked eye. Substantially diminished brilliance to the diamond. Rarely used for jewelry purposes

Choosing the “Right” Clarity Grade

A diamond’s clarity grade has a significant impact on its price. IF (“Internally Flawless”) and F (“Flawless”) diamonds are the rarest and exhibit no flaws that can diminish their brilliance—thus, they are considered exceptionally beautiful and can command great prices. However, a diamond doesn’t have to be flawless to be beautiful. Diamonds in the VVS and VS ranges are beautiful, rare stones that display no visible imperfections and represent a significant cost savings over IF and F diamonds. Diamonds in the SI range offer, even more, cost savings, and many display no imperfections visible to the naked eye. Even some I1 stones display no visible flaws to the unaided eye that would detract from their brilliance or beauty. When deciding what clarity grade to purchase, you need to take into account your budget, and weigh how important the other elements of the “4C’s” (carat weight, color, and cut) are to you. Obviously, you want to buy the best quality diamond you can afford.

Diamond Stud Source recommends that in terms of clarity, you purchase an “eye clean” diamond – one with no surface blemishes or inclusions visible to the naked eye that would diminish your stone’s brilliance or beauty.

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Finding the Right Diamond Shape

Sometimes, people refer to a diamond’s “cut,” when what they really mean is its shape. Although diamonds are available in many different shapes, the most common and popular, by far, is the round brilliant. According to the Diamond Promotion Service, more than 75% of all diamonds sold are round. The reason for this is that many experts consider round the “ideal” shape for a diamond because it maximizes a stone’s sparkle. However, non-round diamond shapes, called fancy shapes, are beautiful in their own right – and they allow the wearer to express their unique style and personality.

Round Brilliant – A 58-faceted shape featuring a facet arrangement that appears to radiate out from the center of the diamond toward its outer rim, maximizing its brilliance. The round brilliant diamond is a timeless, classic shape that is appropriate for any outfit and for any occasion.
Princess – A square or rectangular shape with numerous sparkling facets. The princess is a relatively new shape and is particularly popular in solitaire engagement rings and diamond stud earrings. Because of its design, this shape requires more weight to be directed toward the diamond’s depth than a round brilliant in order to maximize brilliance. A princess diamond offers its wearer a more modern, individual look compared to the classic round diamond.

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What Is A Diamond Certificate?

A diamond certificate, also known as a diamond grading report, is a professional evaluation of a diamond’s quality and unique characteristics. This certificate, or “cert,” as it is often called in the diamond and jewelry industry, provides proof of a diamond’s identity. The best, most accurate diamond certificates are issued by independent accredited gem labs that were not involved in the purchase or sale of the diamond.

The Gemological Institute of America (GIA), the European Gemological Laboratory (EGL-USA), and the Gemological Institute lab (GIL). These laboratories have a longstanding history and reputation for strict, consistent, unbiased third-party diamond grading. Every diamond we sell at Diamond Stud Source is thoroughly analyzed and graded by either of these highly regarded independent laboratories and comes with one of their comprehensive diamond certificates.

Why do I Need a Diamond Certificate?

There are several reasons why you should only purchase a diamond that comes with a certificate issued by an independent gem laboratory like GIA or EGL-USA or GIL:

  • While a certificate doesn’t state a monetary value for your diamond as an appraisal would, it gives you a tangible document that attests to the quality and authenticity of your stone.
  • A certificate allows you to “comparison shop” to determine which diamond is a better value for you, based on its quality and unique characteristics.
  • A certificate is used by appraisers to help gauge a stone’s replacement value for insurance purposes should it be lost, stolen, or damaged.

What’s in a Diamond Certificate?

Some of the key elements you’ll find in a standard diamond certificate include a plotted diagram of the stone, listing all of its significant characteristics, such as shape, carat weight, color, clarity, exact measurements and proportions, imperfections, and the quality of the stone’s polish and symmetry. The report may also contain comments about the presence or absence of fluorescence in the diamond and the quality of its cut, as well as its unique laser-inscribed identification number or other laser-inscribed information.

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Diamond Care

Diamonds are the hardest substance known, but you need to take proper care to keep your diamond intact for a lifetime.

Keep your diamonds away from chlorine bleach or other household chemicals, as they can cause buildup that will dull the surface of the diamonds, and they can damage and discolor the mountings on your diamond studs. We suggest that you clean your diamonds on a consistent basis to keep them brilliant and refractive.


We suggest that you store your diamond jewelry in individual jewelry cases, soft cloth pouches, or in separate compartments in your jewelry box. Diamonds that are improperly stored can damage and scratch each other.


Routine home care of your diamonds supplemented with periodic care results is very beneficial for your diamonds. You can use a solution of one part ammonia and six parts water to clean your jewelry at home. To loosen dirt and gently increase the brilliance of your diamonds, gently scrub your diamonds with a soft brush. Avoid brushing the metal itself, as this may cause it to scratch. We recommend that you periodically have your diamonds cleaned professionally.

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