Round Cut Diamonds: Shape, Cut, Color, Clarity, Proportions

A Round Cut Diamond is the most traditional diamond cut used for symbols of commitment between loved ones, and for many other timeless jewelry pieces. With asymmetrical and uniform shape, Round Cut Diamonds have a total of 58 facets, qualifying them as a brilliant cut. This brilliance of the round cut is shown through its incredible white light reflection capabilities. It is the most popular diamond cut, with 50% of all diamond sales being round cuts.

The faceting found in Round Cut Diamonds gives them better color and inclusion, making them more desirable than other diamond cuts. The fire and brilliance found in a Round Cut Diamond simply cannot be matched.

The Round Cut Diamond and its brilliance make it the most versatile of all cuts, in both style and value. It has more light reflection and brilliance than any other cut and is the ideal balance of color, cut and clarity, playing well with many budgets.

The Brilliance of a Round Diamond Cut

The circular shape and cut allow the 58 different eye-catching facets to reflect and maximize light from all angles, which is why it is known as a brilliant diamond. The cut itself is the most widely worn shape on the market and can be worn day or night, at any occasion or age.

When it comes to the quality of the beauty of a diamond, cut is the most important element to consider. Proportions of a cut will determine the diamonds ability to provide brilliance by reflecting light.

A Round Cut Diamond which is cut for maximum brilliance will allow for light to strike each pavilion and reflect back through the crown and table to the eye. When a Round Cut Diamond is cut well-proportioned, the facet angles will optimally reflect white and colored lights, flawlessly.

If a round diamond is cut too shallow, the incoming light will strike the pavilion at a lower angle and travel through the diamond to exit at the sides, not reflecting through the table to the eyes. This means the light is escaping, and therefore the diamond will lack fire and brilliance.

Alternatively, if a Round Cut Diamond is cut too deep, the light will enter and strike the pavilion at a much sharper angle, this causes the light to exit through the bottom of the diamond and not through the table. This will cause the diamond to appear dull.

It is so important when evaluating the cut quality of a round diamond, to ensure that it is not cut too shallow or too deep.

When it comes to grading the cut of a diamond, the GIA (Gemological Institute of America) grading system is highly regarded to follow. It is a well-respected grading entity that grades Round Cut Diamonds on the following scale:

Excellent

This will provide the highest level of brilliance and fire
All incoming light is reflected through the table

Very Good

Immense fire and brilliance
Most of the light entering the diamond reflects through the table

Good

Ample brilliance
Some light reflects through the table

Fair

Minimal brilliance
Light exits through the bottom and side of the diamond

Poor

No sparkle or brilliance
Light escapes through the side and bottom of the diamond

Similar to the round cut is the Old European Cut. This cut is close to the round cut but was designed prior to the creation of modern diamond technology. Old European Cuts have smaller tables, deeper proportions, and heavier crowns than the round cut and follow the following quality guidelines:

Size of table – Less than or equal to 53 percent

Crown angle – Greater or equal to 40 degrees

Bottom half facet length – Greater than or equal to 60 percent

The cut of a round diamond will greatly affect the quality of the beauty. It is important to spend time considering this, and if you have to stick to a budget, try and reduce the carat weight instead of compromising on the quality of the cut.

The following are the parameters set as a guideline to better understand the quality of a cut for a Round Cut Diamond:

	Excellent	Very Good	Good	Fair	Poor
Depth (%)	59-62.3	58-58.9 / 62.4-63.5	57.5-57.4 / 63.6-64.1	56.5-57.4 / 64.2-65	Less than 56.5 Greater than 65
Table (%)	53-58	52-53 / 58-60	51 / 61-64	50 / 65-69	Less than 50 Greater than 69
Pavilion Depth	42.8-43.2	42-42.7 / 43.3-43.9	41-41.9 / 44-45.5	39-40.9 / 45.6-48	Less than 39 Greater than 48
Crown Angle	34-34.9	32.1-33.9 / 35-35.9	30.1-32 / 36-37.9	23-30 / 38-40.5	Less than 29 Greater than 40.5
Girdle	Thin – Slightly Thick	Very Thin – Slightly Thick	Very Thin – Thick	Very Thin – Very Thick	Ex Thin – Ex Thick
Cutlet	None	Very Small	Small	Medium	Greater than Medium

Analyzing Round Cut Diamond Color

When it comes to Round Cut Diamonds, color is slightly difficult to distinguish due to the round cut reflecting more light than any other diamond shape. The high level of brilliance and the multiple facets conceal color, so the color should be considered but should not be a complete deciding factor.

While coloring in diamonds can add value in some cases when slight coloring is present, less natural color light is reflected back through to the eye. Therefore the less color a white diamond has, the more radiant and valuable it is.

Some general rules about diamond color:

The value of a diamond is dependent on the absence of color
The color grade of a diamond should be graded by a professional
Grade and value of a diamond change between colored and colorless diamonds
The ring setting can change the perception of color in a diamond

The GIA has a grading scale for diamond color, ranking them from D-Z

D, E, F Colorless – D is the highest on the color grade, meaning the diamond has nearly no color. E and F grades are also nearly colorless. Round Cut Diamonds with a grade of D, E or F should be set in platinum or white gold. Yellow gold might detract from the colorless diamond.

G, H, I and J Nearly Colorless – G-J diamonds appear colorless to the naked eye, but some tints of color may exist. Taking this into consideration, these diamonds should be set in white gold or platinum to reduce the effects of color reflecting off of yellow gold. These diamonds are nearly 10-15% cheaper than D-F diamonds and the difference is hardly noticeable to the eye.

K, L, M Faint Tint – This graded diamond has a slight yellow tint to the naked eye. These warmer colors are better set in a yellow gold setting. The price of these diamonds is often reduced by 50% than those of the D-F grade.

N – R Very Light Tint – N-R diamonds have a noticeable yellow or brown tint and are available at a much lower price.

S – Z Light Tint – These diamonds have an easily noticeable tint of yellow or brown and are not recommended diamonds to purchase.

The setting you use for the diamond can have an effect on the color appearance. Near colorless diamonds can have a slight tint when set in yellow gold, so it is wise to take this into consideration when choosing a diamond and then deciding on a setting.

Clarity and Quality of Round Cut Diamonds

The clarity of a diamond refers to the visual appearance of the blemishes and inclusions in a stone. There is a grading chart from the GIA to consider when deciding on a diamond:

IF – Internally Flawless

VVS1 – Very Very Small Inclusions 1

VVS – Very Very Small Inclusions 2

VS1 – Very Small Inclusions 1

VS2 – Very Small Inclusions 2

SI1 – Small Inclusions 1

SI2 – Small Inclusions 2

I1 – Inclusion 1

I2 – Inclusion 2

There are five factors that play a part in the overall clarity grade of a diamond.

Size

The size of the blemish or inclusion plays a big role, as the larger the inclusion, the bigger impact it will have on the Round Cut Diamonds clarity.

Nature

Nature refers to the type of inclusion present. It factors in the depth and other characteristics found within the diamond. If there is something found on the surface of the diamond which has not penetrated within the diamond, it is considered a blemish and not inclusion.

Number

The number affects the clarity grade, as the grade will be much lower if there are several clarity characteristics present.

Location

The location refers to where the inclusion is found on the diamond. If it is found close to the center of the table, the clarity grade will be heavily impacted. However, if the inclusion is found closer to the girdle, the inclusion will be more difficult to see. Then if the inclusion is found near pavilions where the diamond can reflect, the inclusion will be reflected.

Relief

This refers to how noticeable the inclusion is in relation to the contrast of the diamond. The higher the relief, the darker the color which can have an effect on diamond grading.

For Round Cut Diamonds, you need to determine if the diamond is eye clean, instead of simply looking at a grading chart. A VS1 and a VVS2 diamond might look the same to you, without any inclusions, but the cost of the VVS2 diamond will be higher. This will give you the same quality diamond to the eye and might help you save on costs by purchasing the VS1.

When looking for inclusions, it is important to note their locations. If the inclusions or blemishes are found on the perimeter, they will be more difficult to see through the diamond’s table. Blemishes found on the perimeter might also be covered by prongs of the jewelry when the diamond is set.

If you are sticking to a budget, it will be worth your while to purchase a diamond that is eye clean, and not going for a higher clarity than this. Anything rated higher will be more expensive, and the difference will be unnoticeable.

How Carat Weight Works and What to Look For

Diamonds are sold by carat weight, which is a unit of weight and not size. Originally, diamond traders used carob seeds as a unit of measurement, which is where the word carat comes from. A carat is equal to 0.2 grams.

Two diamonds with equal carat weights can have vastly different costs. This is because other factors such as color and clarity weigh a big role in determining the price. The carat weight is often sought after as the main deciding factor of a diamond, as many people opt for bigger diamonds on rings rather than the possible clarity or color grade.

Larger carat weight diamonds hold a much larger price tag, as the larger the diamond is, the rarer it is considered. In fact, less than one in one million mined stones are large enough to end up in a finished 1-carat diamond. The larger the carat weight, the more you will pay as diamonds are sold on a price-per-carat basis.

While many think the size of a diamond increase like the price with carat weight, this isn’t exactly true. The diameter of a diamond does not increase exponentially with weight. The following diagrams illustrate this:

Carat Weight	1.00	2.00	3.00
Diameter (mm)	6.50	8.20	9.40
Crown (mm²)	33.2	52.8	69.4

The depth and diameter, including crown size, play a big role in the overall size appearance of a round diamond. One diamond might have a lower carat weight than another diamond which is deeply cut, but it may have a larger diameter which makes it appear larger in size.

It is a good idea to look for diamonds that fall just under the popular carat weights (1/2 carat, ¾ carat, 1 carat, etc). These diamonds are often sold at a discounted price as they are just shy of the popular weights. While the price might be lower, it can be very difficult to distinguish between a .90 carat diamond and a diamond weighing 1.0 carat. These two different weight carats might even have the same diameter, with the larger diamond having a deeper cut, making them appear to be the same size and weight when viewed from above.

Tips on Buying a Round Diamond

Once you have decided on a Round Cut Diamond, you can start working through different determining factors to find the perfect diamond within your budget.

Decide on carat weight. If you are after a 1.0-carat diamond, look for this or as close as possible, such as a 0.90-carat weight.
Start by looking at the highest quality diamond in the weight minimum you have decided on. To cut down on your budget, consider the following in this order:

Lower the clarity grade on the diamond you are looking for, however, do not go lower than a VS2 for a Round Cut Diamond.
Lower the grade of the color next, but do not go lower than an H grade.
Lower the cut of the diamond, but do not go below Very Good with a round diamond, as this will affect the quality overall.

Round diamonds are always a great choice cut as they have the best brilliance and scintillation than other shape cuts, and they accommodate almost any ring setting and will never go out of fashion.

Below is a good table to follow when purchasing a Round Cut Diamond, as it shows ideal and acceptable proportions, allowing you to make an informed decision when purchasing a good quality diamond.

	Ideal Proportions	Acceptable Proportions
Depth (%)	60.2 – 62.7	57.0 – 64.0
Table (%)	53.0- 57.0	53.0 – 64.0
Polish	Very Good – Excellent	Good – Very Good
Symmetry	Very Good – Excellent	Good – Very Good
Girdle	Thin – Medium	Thin – Thick
Culet	None – Very Small	None – Medium

Certificates to Consider When Buying a Diamond

It is so important to have the right certificates issued when you purchase a diamond. This helps prove its value and worth, as well as its authenticity. A diamond appraisal will take note of the carat weight, the shape, the cut, the color, the clarity and the measurements of a diamond.

The primary importance of having a diamond appraisal is to establish the actual value of the diamond for insurance purposes. A diamond will not be insured unless they are provided with a recognized appraisal document.

If you want to have your diamond independently appraised, there are a few things to look for:

True Independence – Not affiliated or employed with a jewelry retailer
Graduate Gemologist (certified by the GIA)
A member of a reputable appraisal association such as ISA, ASA or NGJA
Someone who conforms to USPAP (Uniform Standard of Professional Appraisal Practice)
A full-time appraiser who is experienced in appraising natural and synthetic gems
A flat fee structure which is not a percentage of the value of the diamond
An open environment with the diamond present for you to view

Round Cut Diamond Fluorescence

The fluorescence of a diamond is its tendency to emit a soft glow when put under ultraviolet light (black light). Up to 30% of diamonds have some fluorescence. However, colorless diamonds on the scale of D-F are sold at a discount as any fluorescence is viewed as a defect.

Fluorescent glow usually appears blue, which means it can make diamonds of L-M color seem up to one grade whiter. This makes these diamonds sell at a higher premium if they have medium to very strong fluorescence.

To summarize, fluorescence is not a big factor when buying a diamond, as the slight effects are in fact mildly positive. The only caution to take is buying diamonds which have strong fluorescence in the D-F and G-H range, which should not have enough color to offset the degree of fluorescence.