Princess-Cut Diamonds: the Ultimate Guide


Summary
Nearly as brilliant as the ubiquitous round, the princess cut brings a modern, edgy look to diamond jewelry. However, the lack of laboratory cut grades make purchasing princess-cut diamonds a bit more difficult. We’ll teach you how to fine tune your searches at James Allen and Blue Nile so you can find the diamond that’s best for you. Learn why princess cuts may have an advantage over rounds and how to choose a high-quality stone for your engagement ring.
Reading time: 9 min 23 sec
princess-cut diamonds - bypass setting engagement ring
Amid swirls of white gold, the sharp angles of this 0.5-ct princess-cut diamond command attention. © CustomMade. Used with permission.

Round vs Princess-Cut Diamonds

Ultimately, whether you choose a round or princess cut for your engagement ring may be a matter of personal style. However, you should also take some practical considerations into account.

Price

It’s no secret that princess-cut diamonds are less expensive than rounds. This is because of the octahedral shape of a rough diamond. When gem cutters split the rough in half, they can cut two princesses with minimal waste. (The two halves look like pyramids). In contrast, round-cut diamonds waste more rough, so they cost more than princess cuts. Based on these 1-ct ideal-cut, G color, VS2 clarity diamonds, a princess-cut diamond can cost 30% less than a round of equivalent carat weight!

Sparkle

Princess cuts can show exceptional brilliance. However, they still don’t live up to the brilliance of round diamonds. No fancy cut can match their optimal light performance. So, while princess cuts can have great sparkle, they’ll never sparkle better than an ideal round.

Size

If you compare a princess and round diamond of the same carat weight, you’ll see that the round will have a slightly larger face-up surface area. However, princess cuts can often appear larger, since they have such large diagonal measurements.

That said, you’ll still be able to get a significantly larger princess cut than a round cut while staying in your engagement ring budget.

Durability

Since the corners of a princess-cut diamond may snag, they’re likely to chip. Their corners should always be protected with prongs to reduce the risk of damage to the stone. Although round diamonds can still chip, they don’t have any weak points so prone to chipping.

Engagement Ring Styles for Princess-Cut Diamonds

Of course, you can’t consider different diamond shapes without taking style into account! Although round diamonds are a standard, classic shape, princess-cut diamonds are the most popular of the fancy shapes. They work well in many styles, including solitaire and three-stone engagement rings.

The brilliance and geometric shape of princess cuts make them a great choice for sleek modern styles.

princess-cut diamonds - modern style engagement ring
This geometry of this pavé ring complements a princess-cut diamond well. © James Allen. Used with permission.

However, princess-cut diamonds can also work well in ornate vintage styles.

princess-cut diamonds - vintage inspired engagement ring
Flanked by alexandrites in a floral style engagement ring, this 0.51-ct princess-cut diamond shines. © CustomMade. Used with permission.

Judging the Princess Cut

A diamond’s sparkle comes primarily from the quality of its cut. Unfortunately, you’ll find evaluating a princess cut is bit more difficult than evaluating a round. Most gemological laboratories don’t grade the cut quality of fancy cuts, including princesses.

While the James Allen and Blue Nile websites do provide cut quality grades for princess cuts, these are less robust than those for rounds. Still, they make it possible to weed out some of the less impressive stones. Compare this “Good” cut to a “True Hearts” cut. There’s no denying the difference!

If you’re looking for an easy way to focus your search, filter the James Allen database for princesses with “True Hearts”-quality cuts only. Your results will show you princess-cut diamonds that perform well. However, you might miss out on a deal by ruling out the next-best cut grades!

Anatomy of a Princess Cut

All fancy cut diamonds have too many variations for standardized cut grades. Unlike the round brilliant, there’s no set expectation for what a princess cut should look like. Princess cuts can differ by the pattern on the crown as well as the number of cuts on the pavilion. While neither impacts value or quality, you’ll just prefer one to the other.

The crown of a princess — the part on the diamond that faces up when you look at it — can have either French corners or bezel corners. (Princess cuts with bezel corners have diamond-shaped facets extending from the table corners to the stone corners; those with French corners have star facets that point to the stone corners).

Since bezel corners are more durable, stick to this design unless you have a strong preference for French corners.

On the pavilion or underside of a princess cut, chevron shapes produce the diamond’s brilliance. Princess cuts can have two, three, or four chevrons. Stones with two chevrons produce larger, bolder flashes of light and color, while four chevrons will scintillate more, but with smaller facets. Those with three chevrons create a middle ground.

princess-cut diamonds - crown styles and chevrons
Princess-cut diamonds can have slightly different cuts, with different crown styles or different numbers of chevrons. Adapted from “Princess Cut Chevron Comparison” by Anniewill. Licensed under CC By-SA 3.0.

Depth Percentage

When a diamond is cut too shallow or too deep, the light that enters the stone doesn’t properly reflect back to your eye. When searching for a princess cut, limit the depth percentage to 65-75%.

Table Percentage

The table percentage describes how large the top facet is compared to the width of the diamond. Keeping the table to 75% and below will help you find a great princess!

A small minority of diamond dealers prefer a princess with a very small table, under 68%. If you prefer small tables, prepare to do some searching, as these are less common than larger tables.

Length-to-Width Ratio

For a square princess cut, stick to length-to-width ratios (L/W) of 1.05 and below. Above 1.05, the diamond appears off-shape.

princess-cut diamonds - off shape
With a L/W ratio of 1.09, this 3.01-ct diamond appears slightly off — not square enough and yet not rectangular enough. © James Allen. Used with permission.

Rectangular princess-cut diamonds should be sufficiently rectangular that they don’t simply appear off-shape. At a L/W ratio of at least 1.2, the diamond will appear rectangular.

Girdle Thickness

Because of the fragile corners, check that the girdle is thick enough to support prongs. While most princess girdles will support prongs, “Extremely Thin” girdles make the diamond more susceptible to breaking.

Polish and Symmetry

Polish and Symmetry ratings should be “Good” or better. There’s no noticeable difference between “Good” and “Excellent” in these categories.

Clarity

Even diamonds have imperfections. Clarity grades describe how noticeable these imperfections are. For a princess cut, an SI1 or VS2 diamond (slightly included or very slightly included) will give you eye-clean clarity at a great price point.

princess-cut diamonds - si1 clarity
This is a worst-case SI1 clarity diamond, with a large, dark inclusion right in the center of the stone. Because of its placement, this diamond may not be eye-clean. © James Allen. Used with permission.

SI2 and I1 (included) diamonds can also be eye-clean, and could make great options for those on a tight budget. However, you’ll normally find relatively few princess cut-diamonds in these clarity grades. If you’re looking at these clarity grades, avoid dark inclusions near the center of the stone.

princess-cut diamonds - I1 clarity
Because the crystal inclusion in this I1 clarity 0.90-ct diamond isn’t too dark, it’s likely not noticeable to the eye. However, it’s a good idea to consult the experts to make sure the inclusion isn’t at the surface, which can make the stone more likely to break! © James Allen. Used with permission.

In addition, watch out for inclusions in the corners of a princess cut. Inclusions in these areas make the corners even weaker and more likely to break.

Always take advantage of the free expertise at James Allen to help you determine whether the diamond will be eye-clean or more susceptible to chipping.

Color

Princess-cut diamonds, like other fancy shapes, show color more than a round diamond. Still, there’s no reason to pay extra for the top color grades. Though there’s a slight difference in color, it’s impossible to notice unless you’re looking at the diamonds side-by-side.

For princess-cut diamonds set in either white gold or platinum, we recommend an H or I color diamond to make the most of your budget.

princess-cut diamonds - I color in white gold
With a 0.80-ct I color diamond, this white gold pavé rope ring looks great! © James Allen. Used with permission.

For rose gold and yellow gold rings, a J color diamond will look great and save you some money!

princess-cut diamonds - J color in yellow gold
The slight warmth of the 0.65-ct J color diamond plays well in this yellow gold twisted shank ring. © James Allen. Used with permission.

Since diamond color grades come from their body color, rather than their face-up color, some diamonds below J color will face up whiter. Though it will take some time and effort, searching for these diamonds can be worth the discount for those on a tight budget!

princess-cut diamonds - K color
In this rose gold cross-prong solitaire ring, this 1.00-ct K color diamond faces up only slightly off-color. © James Allen. Used with permission.

Sorting Through the Options

Still not sure where to start? Just click here to search James Allen’s diamonds based on our recommendations. Once you add in your budget, you’ll see how many options you have — and whether you need to broaden your parameters!

Lower clarity grades are a great way to stretch a budget, but always ask the experts if the diamond will be eye-clean or susceptible to breaking.

Compromising on diamond color can be trickier, but it’s a great option for rose gold or yellow gold rings.

If you’re looking at larger sizes, you may have to look at higher clarity and color grades to get the most sparkle in your diamond!

Buying Princess-Cut Diamonds Online

When making a purchase online, use a reputable dealer and look at their policies on returns, exchanges, and resizing. Whether you’re buying princess-cut diamonds for an engagement ring or earrings, both James Allen and Blue Nile have large selections to choose from. In addition, both companies utilize 360° magnified videos of their diamonds. These allow you to scrutinize a diamond’s performance, clarity, and color before you buy.

However, James Allen has a larger selection of rings. This will help you select an engagement ring design that matches your style. Their in-house diamond experts will also review your diamond choices with you. Just what you need to make sure that your diamond is eye-clean and performs well in your ring!

If you’re looking for rectangular princess cuts, Blue Nile does have a slight advantage. Their search function allows you to filter for L/W ratios.

If you just can’t seem to find what you want, consider getting a custom design at CustomMade. Their jewelry experts will help you create your perfect ring!

About the author
Addison Rice
A geologist, environmental engineer and Caltech graduate, Addison's interest in the mesmerizing and beautiful results of earth's geological processes began in her elementary school's environmental club. When she isn't writing about gems and minerals, Addison spends winters studying ancient climates in Iceland and summers hiking the Colorado Rockies.
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