Princess Cut Diamond: A Buying Guide

Princess cut diamond.

Princess cut diamonds are the second most popular diamond shape. Princess cut diamonds possess the gorgeous sparkle of round brilliant diamonds in a distinctive square shape. They offer a contemporary look and the flexibility to work in almost any style of ring.

Princess Cut Diamond

Princess cut diamond.

The princess cut diamond, first created in 1980 by Betzalel Ambar and Israel Itzkowitz, is the most popular fancy cut, especially for engagement rings. Like round cut diamonds, princess cut diamonds are a good choice for their flexibility in working in almost any style of ring. Much like the round brilliant, the princess cut is a classic and elegant shape, although with its sharp corners boasts more of a contemporary edge. Of all of the square cuts, the brilliant cut princess (along with the radiant cut) comes the closet to achieving the fire, brilliance and simple elegance of a round diamond, making it an ideal combination of unique shape, sparkling appearance, and relative price value.

Princess Cut Diamond Buying Guide


Princess Cut Diamond Quick Guide

Unique Features
Contemporary square cut, most brilliant of all square shapes
Usually 57 or 76
L/W Ratio
1.00 - 1.05 (square) > 1.05 (rectangular)
1970's, developed from barion & quadrillion cuts
Expert Tip
Ideal for long fingers and eternity bands

Princess Cut Diamond Ring

Princess Cut Diamond Ring

Princess cut diamond ring.

Princess Cut Diamond Features

Princess Cut Diamond Features

Princess cut diamond features.

The princess cut is the square version of the brilliant round cut usually comprised of either 57 or 76 facets with a typical ratio of 1.0 to 1.05.

Its pyramidal shape with four bevelled sides creates more light dispersion than any other square shaped diamond, making it popular for both solitaire engagement rings and earrings.

As it is a patented cut, it may be referred to as a Square Modified Brilliant on a laboratory certificate (eg. GIA or AGS), or a Rectangular Modified Brilliant if it has a ratio greater than 1.05.

Princess Cut Diamond Expert Guide

Because of its extra facets, the princess cut can disperse more light through the diamond, this serves to hide inclusions more efficiently, making it the most brilliant of all square and rectangular shaped diamonds. It is also a popular cut for wedding bands because the diamonds can be arranged side by side without any gaps, making it ideal for an eternity band too. Furthermore, due to its sharply squared corners, the princess is an ideal cut for long fingers.

Princess cut diamonds also tend to have a slightly lower price per carat than round cut diamonds. This is because the four sided pyramid shape of the princess cut diamond is similar to one half of the octahedron rough diamond from which a princess diamond is cut. This similarity allows two equally sized princess cut diamonds to be cut from the same rough diamond with relatively little waste (roughly 60% of the weight of the original rough diamond is retained after cutting). The greater efficiency, or yield, translates to a lower price.

Carat for carat, the crown surface area of a princess cut is about 10% less than a same weight round diamond. However, the corner to corner measure of a princess cut is typically 15% greater than the diameter of a same weight round diamond, creating the illusion of greater size.

Princess Cut Diamond Symmetry & Polish

Princess cut diamond symmetry & polish.

The diamond symmetry of the facets is the main factor to create the beauty of the cut. The facets on the right and left halves of the diamond should have the same shape and size. All the points of the facets should meet, there should not be missing or extra ones. The more symmetrical the facets. the more beautiful the diamond.

The princess is traditionally a square cut (four sides of equal length). However, many princess cut diamonds are slightly rectangular, though this is often hard to detect. All other things being equal, the more rectangular a princess cut diamond, the lower the price. Many buyers actually prefer a slightly rectangular princess cut; it's all about finding what is most pleasing to you. Any length to width ratio of 1.05 or less will appear square to the naked eye. If the princess will be set with side diamonds, a length to width of 1.05 - 1.08 may still look square, as the side diamonds will create the illusion of greater width in the center diamond.

A princess cut diamond should always be set with prongs that protect the four corners (the most likely location for chipping). Because these corners were once near the outer edge of the rough diamond, flaws such as naturals, extra facets, and other inclusions may be located here. Since the corners are covered by the prongs, these flaws will be invisible once the diamond is set. The only remaining concern would be if the flaws are significant enough to affect the stability of the diamond (this is extremely rare, however). Most other square cuts (such as emerald, asscher, and radiant) have cropped corners.

Princess Cut Diamond - Cut Guide

The quality of the cut is the most important factor in maximizing the brilliance and fire, meaning it greatly affects the appearance of a diamond.

All of the square cuts, the princess cut along with the radiant cut comes the closest to achieving the fire and brilliance of a round diamond, making it an ideal combination of unique shape and sparkling appearance.

Since the GIA doesn't provide any information other than polish and symmetry on a princess diamond cut quality, it is important to look for a diamond that has even sides and equal proportions.

The chart below serves as a general guideline for evaluating the cut of a princess diamond. A common rule of thumb with princess cut diamonds is to avoid those with a table % that is greater than the depth %:

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Princess Cut Diamond Excellent Very Good Good Fair Poor

Depth refers to the distance between the culet and the table when a diamond is viewed from the side.

The depth % of a diamond is calculated by dividing the depth of the diamond by the width of the diamond. So, if a diamond is 3 mm in depth, and 4.5 mm in width, its depth % is 66.7.

The lower the depth %, the larger a diamond of a given carat weight will appear when viewed from above (since more of the diamond's size is in its width vs. in its depth).

Depth % is incorporated in the cut grade of a diamond. For this reason, when purchasing a diamond, use the cut grade first (since it balances multiple measurements, not just depth %). Once two diamonds of equal cut are being compared, consider depth % as a further refinement.

Learn more about the anatomy of a diamond.

64 - 75 64 - 75 58 - 63.9 or 75.1 - 80 56 - 57.9 or 80.1 - 84 <56 or >84

The table is the uppermost, flat surface of a diamond, which runs parallel to the plane of the girdle.

The table % of a diamond is calculated by dividing the width of the table facet by the width of the diamond. So, if the table facet is 3 mm across, and the diamond is 4.5 mm wide, its table % is 66.7.

Table % is incorporated in the cut grade of a diamond. For this reason, when purchasing a diamond, use the cut grade first (since it balances multiple measurements, not just table %). Once two diamonds of equal cut are being compared, consider table % as a further refinement.

Learn more about the anatomy of a diamond.

62 - 72 59 - 66 or 73 - 75 56 - 58 or 76 - 82 53 - 55 or 83 - 85 <53 or >85

A diamond's symmetry is the arrangement, size, and shaping of diamond's facets. The facets are the flat planes that run along the surfaces of the diamond. Symmetry is angles and lines that form the placement of the facets. Nowadays, symmetry is completely controlled by the manufacturing process. Machines very carefully cut diamonds to produce the most accurate shapes. However, at times the diamond cutter will leave a symmetry imperfection in the diamond in order to prevent a different inclusion from showing in the finished diamond. Symmetry is a subset of the diamond's cut grade.

Learn more about diamond symmetry.

Good to excellent Good to excellent Good to excellent Fair to Excellent Poor to Excellent

The term "polish" refers to the overall condition of the surfaces of a finished diamond. A rating is assigned based on the amount of polishing lines that are visible. These polishing lines are caused by very small diamond crystals which are embedded in the polishing wheels used by diamond cutters to polish the surface of the diamond after cutting. Diamond polish is important because it can affect the degree to which light is able to pass through a diamond, rendering it more or less brilliant. Diamonds that are laboratory certified with a good, very good, or excellent polish rating are the most desirable. Diamonds that have poor polish will be less brilliant and not as desirable or valuable. Reputable jewellers diamonds are graded after examining the diamond facet by facet.

Learn more about diamond polish.

Good to excellent Good to excellent Good to excellent Fair to Excellent Poor to Excellent

The girdle is the outer edge of the diamond, where the crown (top) meets the pavilion (bottom).

A girdle may be faceted (a series of tiny polished sides going around the diamond), bruted (a single continuous unpolished surface going round the diamond; no longer common), or polished (a bruted girdle that has been polished smooth). Whether a girdle is faceted, bruted, or polished usually has no impact on the appearance or value of the diamond.

The girdle is described according to its width. Often, the width of the girdle varies at different points around the diamond, and is quoted in a range designating the thinnest and thickest point along the girdle (e.g. "Thin - Medium" means the diamond's girdle varies in width from thin at the narrowest point to medium at the widest point).

Learn more about the anatomy of a diamond.

Very Thin - Slightly Thick Very Thin - Slightly Thick Very Thin - Thick Very Thin - Very Thick Ex. Thin - Ex. Thick

The culet (pronounced cue-let) is the small area at the bottom of a diamond's pavilion. The culet can be a point or a very small facet sitting parallel to the table.

The culet size as determined by the GIA, is shown using the following scale:

None, Very Small, Small, Medium, Slightly Large, Large, Very Large.

Any culet size of Medium or smaller will be invisible to the naked eye, and have no negative impact on a diamond's appearance. However, if a culet is Slightly Large or larger, it may allow light entering from the crown to pass straight through the culet facet, reducing the diamond's brilliance. This may also make the culet appear as an inclusion, or create a dead area on the diamond where the light is escaping through the bottom.

Learn more about the anatomy of a diamond.

Very Small Very Small Small Medium > Medium

The length to width (L/W) ratio is calculated by dividing a diamond's length (the longer measure) by its width (the shorter measure that runs perpendicular to length).

For example, an Oval Cut diamond that is 5.00 mm in length and 3.3 mm in width will have a L/W ratio of 1.50 (5.00/3.33). A perfectly round or square diamond will have a length to width ratio of 1.00, but many will be off slightly since they are often not perfectly cut. Any L/W ratio of 1.05 or less will appear perfectly round or square to the naked eye.

L/W ratio is more commonly used in fancy shapes. There is no "ideal" L/W ratio in a fancy shape diamond. What is important is what looks pleasing to you.

1.00 - 1.03 1.00 - 1.03 1.04 - 1.05 1.06 - 1.08 > 1.08

Princess diamond cut guide.

Princess Cut Diamond Ratio

Princess cut diamond length to width ratio.

Princess Cut Diamond - Color Guide

Evaluating color in princess cut diamonds is subjective. Keep in mind that many buyers may actually prefer the ever so slightly warmer colors of a G-H diamond over the cool colorlessness of a D-F diamond. In fact, most of the premium in price associated with princess cut diamonds at the higher end of the color scale is driven by supply and demand; customers want the D-F color grades, and are willing to pay a premium to get them. In a world without diamond color grading, the price premium for higher grades would be much lower, as the actual differences in color are difficult to perceive.

Since the princess cut is close to the round brilliant cut in terms of brilliance and sparkle it tends to hide color imperfections in the diamond rough, meaning it is harder to evaluate the true color of the diamond. This gives you the advantage to opt for a diamond in a near colorless range and still have a gemstone that looks colorless to an untrained eye.

Smaller princess cut diamonds hide color better than the larger ones do. So depending on the size of a diamond you are going to buy, it's safe to choose a G, H, I or even J color diamond to have a colorless appearance. However, those who prefer actual colorless diamonds need to choose diamonds in the D-E-F color range. The color chart below provides a general guide for evaluating color in princess cut diamonds:

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Princess Cut Diamond Excellent Very Good Good Fair Poor
< .50 ct. D - G H - I J - K L - M > M
.51-1.0 ct. D - F G H - I J - K > K
1.0-2.0 ct. D - F D - F G - H I - J > J
> 2.0 ct. D - F D - F G H - I > I

Fluorescence refers to a diamond's tendency to emit a soft colored glow when subjected to ultraviolet light. Roughly 30% of diamonds fluoresce to some degree.

Colorless (D-F) fluorescent diamonds sell at up to a 15% discount since the fluorescence is perceived as a defect, even though the visible effects of Faint to Medium fluorescence are perceptible only to a gemologist using a special UV light source.

Because the fluorescent glow is usually blue (which is the complementary color to yellow) fluorescence can make diamonds of I-M color appear up to one grade whiter. For this reason, I-M diamonds tend to sell at a slight premium when they possess Medium to Very Strong fluorescence.

Exercise caution in purchasing a diamond with Strong fluorescence in D-F color diamonds or Very Strong fluorescence in G-H color diamonds (which do not possess enough body color to offset the higher degree of fluorescence).

Learn more about diamond fluorescence.

None Faint - Med Strong Very Strong Very Strong

Princess diamond color guide.

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Princess Cut Diamond Color

Princess cut diamond color.

Princess Cut Diamond - Clarity Guide

Like color, evaluating clarity in princess cut diamonds is subjective. GIA provides excellent help with their clarity grades. Still, it is important to understand that each customer will have a unique standard for clarity. Some may be perfectly comfortable with an inclusion as long as they cannot easily see it. Others may insist on a more technically flawless appearance. Because of its brilliance, a princess cut is more forgiving of inclusions than other square cuts (like asscher and emerald), especially when viewed with the naked eye.

As mentioned, In terms of clarity, the princess cut is likewise similar to the round brilliant cut, meaning due to the arrangement of its facets, the princess cut tends to hide inclusions fairly well.

As a general rule, it's harder to see imperfections in smaller princess cut diamonds than in the larger ones. That's why you may purchase a lower clarity grade diamond if it's small enough to maintain an eye-clean appearance. The clarity chart below provides a general guide for evaluating clarity in princess cut diamond:

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Princess Cut Diamond Excellent Very Good Good Fair Poor
< .50 ct. FL - VS2 SI1 - SI2 I1 I2 > I2
.51-1.0 ct. FL - VS1 VS2 - SI1 SI2 I1 - I2 > I2
1.0-2.0 ct. FL - VVS2 VS1 - VS2 SI1 - SI2 I1 > I1
> 2.0 ct. FL - VVS2 VS1 - VS2 SI1 SI2 > SI2

Princess diamond clarity guide.

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Princess Cut Diamond Clarity

Princess cut diamond clarity.

Princess Cut Diamond History & Background

The name "Princess Cut" was originally used in connection with another diamond cut known as the "Profile" cut, which was designed by London cutter Arpad Nagy in 1961. The same name was later used and made popular by Ygal Perlman, Betzalel Ambar, and Israel Itzkowitz in Israel, who in 1979 created the Princess cut (or Square Modified Brilliant) as it is known today.

Other precursors of the Princess cut include the Barion - a square cut with rounded corners created in 1971 by South African cutter Basil Watermeyer, and the Quadrillion - a similar cut with only 49 facets, also created by Perlman, Ambar and Itzkowitz and initially distributed by Ambar Diamonds in Los Angeles. Following several years of optical research, the modern Princess cut was created - a square diamond of 58 facets arranged similarly to those of a round brilliant cut diamond.

Princess Cut Diamond History

Princess cut diamond history.

Learn more about what you need to know in our ultimate buying guide, if you're thinking of buying a princess cut diamond. We break it all down from pricing, other shapes comparison and engagement ring setting choices.