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GIA 4Cs Diamond Blog

GIA 4Cs Diamond Blog

A yellow diamond engagement ring is a stunning choice to celebrate your love. But picking the perfect engagement ring requires knowing about yellow diamonds, mountings, the effect of metals on appearance, treatments and more. We offer help.

Here are a few things you’ll need to know:
A fancy-color yellow diamond falls outside the GIA D-to-Z color range
GIA assigns one of six “fancy” color grades to your yellow diamond engagement ring
Don’t expect a round diamond for your yellow diamond engagement ring
Mountings can make a yellow diamond look darker
The metal used affects the appearance of a yellow diamond engagement ring
Some yellow diamonds might be treated, lab grown or both
Make sure GIA grades the diamond in your yellow diamond engagement ring
A yellow diamond engagement ring is rare because yellow diamonds are rare

 

A fancy-color yellow diamond falls outside the GIA D-to-Z color range

Understanding diamond color is essential before you go shopping for a yellow diamond engagement ring. Most colorless or near-colorless gem-quality diamonds are graded based on the absence of color, using GIA’s D-to-Z diamond color-grading system. Yellow diamonds are considered to be colored diamonds and are graded as “fancy” when they have more color than the Z masterstone.

Here is another important difference between yellow diamonds and colorless diamonds. Diamonds in the D-to-Z range usually decrease in value as the color becomes more obvious. The opposite happens with fancy-color diamonds. Their value generally increases with the strength and purity of the color.

Natural intense yellow heart shaped diamond

Colored diamonds graded Fancy Intense are often prized over those with other fancy grades. This yellow heart shaped diamond speaks of the first blush of love. Photo: Robert Weldon/GIA

A 5.33 carat Fancy Yellow pear shaped diamond.

Fancy-color diamonds are often cut into fancy shapes, like a pear shape, to bring out the color. Sunny days lie ahead for the bride wearing this 5.33 carat (ct) Fancy Yellow pear shaped diamond. Courtesy: 1stdibs.com

 

GIA assigns one of six “fancy” color grades to your yellow diamond engagement ring

The names used to describe colors are often quite subjective. Consider that the color yellow includes variations like butter, lemon, golden and more. To bring objectivity and standardization to the grading of the rare beauties that are colored diamonds, GIA created the GIA Colored Diamond Color Grading System in the 1950s and refined it over the decades. This grading system not only defined the processes for determining a diamond’s color, but it also established the terms, or color grades, for describing it.

GIA’s grading system places most colored diamond in one of nine categories based on the diamond’s hue, tone and saturation: Faint, Very Light, Light, Fancy Light, Fancy, Fancy Intense, Fancy Dark, Fancy Deep and Fancy Vivid. The first three grades aren’t used for yellow diamonds, so the scale for yellow begins with Fancy Light. The majority of yellow diamonds in the jewelry industry are graded Fancy Light, Fancy, Fancy Intense and Fancy Vivid.

In general, the more color a colored diamond has, the better. Fancy Deep and Fancy Vivid diamonds, for example, have more color than Fancy Light diamonds—and are usually more valuable. However, tone (the degree of darkness or lightness of a color) is also important. For example, a diamond that is extremely dark (Fancy Dark) may be less desirable than a lighter stone graded Fancy Intense.
It is not unusual for a yellow diamond to have a hue modifier, such as orangy yellow or greenish yellow. A modifier does not indicate that the color is any less strong or pure.

 A chart shows the subtle transitions in GIA’s color grading of yellow diamonds.

This chart shows the subtle transitions in GIA’s color grading of yellow diamonds. Note, too, that the fancy grades represent a range of color sensations, not a “single” color sensation. Photo: Elizabeth Schrader and C. D. Mengason/GIA

 

Don’t expect a round diamond for your yellow diamond engagement ring

Round diamonds cut in the brilliant faceting style are the most popular diamonds for engagement rings, but you may have a challenging time finding a round stone for your yellow diamond engagement ring. That’s because yellow diamonds typically display a more intense face-up color appearance when they’re cut in a shape other than round. These non-round shapes are called fancy shapes, which include oval, pear, marquise and heart, plus square or rectangular cuts like princess, radiant and emerald.

A 10.12 carat Fancy Vivid yellow pear shaped diamond.

This 10.12 ct Fancy Vivid yellow pear shape is an example of a fancy-shape diamond. This shape was most likely selected to intensify the yellow color. Photo: Elizabeth Schrader/GIA. Courtesy: The Scarselli Family

 

Mountings can make a yellow diamond look darker

If your heart is set on a yellow diamond engagement ring, you will probably look at a number of loose yellow diamonds. Be aware that the yellow diamond that has caught your eye may appear darker when set in a mounting.

Look at the photos below. The diamond on the left in the top image was graded Y–Z range, just on the light yellow/Fancy Light yellow boundary. It is shown next to a Fancy yellow reference diamond. In the bottom image, the larger diamond is mounted in a ring and placed next to the same reference diamond.

An image showing a loose yellow diamond and a mounted yellow diamond.

A yellow diamond is likely to look darker once it’s set in a mounting. Photos: Elizabeth Schrader/GIA. Courtesy: The Scarselli Family

This effect can actually work to your advantage, particularly if you’re deciding between a less expensive “light yellow” diamond at the very low end of the D-to-Z color scale and a more expensive Fancy yellow diamond.

 

The metal used affects the appearance of a yellow diamond engagement ring

Diamonds are highly reflective. Their facets are like tiny mirrors, reflecting their surroundings, which include the color of the ring and the prongs holding the gem. Because of this, the color of the metal will affect a diamond’s appearance.

You’ll typically have three choices when picking a metal for your yellow diamond engagement ring:

Do you want your engagement ring to highlight the color of the yellow diamond? White metals and rose gold will create contrast between the mounting and the stone. White gold makes for a streamlined, sophisticated look. A rose gold mounting will create a warmer contrast.

Do you want your ring to complement the color of the diamond? A yellow gold mounting will harmonize with a yellow diamond. Take a look at Art Deco style engagement rings, Retro style engagement rings and ring styles typical of the Victorian era, times when yellow gold was in fashion, to see if these are designs you’d like to recreate for your yellow diamond engagement ring.

A 4.76 ct Fancy Vivid yellow diamond engagement ring surrounded by a halo of colorless diamonds.

Want your yellow diamond to pop? Set it in a white metal ring. This 4.76 ct Fancy Vivid yellow diamond is so bright that it appears to have captured a ray of the sun. A halo of colorless diamonds surrounds it. Courtesy: 1stdibs.com

A 3.46 ct yellow oval diamond engagement ring set in rose gold.

Rose gold is another way to create contrast with a yellow diamond. In this ring, it acts as a subtle counterpoint to the 3.46 ct yellow oval diamond. Courtesy: 1stdibs.com

A three-stone yellow diamond engagement ring set in yellow gold.

A yellow gold band paired with yellow diamonds creates a harmonious look. The three yellow diamonds set in 18K yellow gold are sure to soothe the eye as they captivate it. Courtesy: Rahaminov Diamonds

 

Some yellow diamonds might be treated, lab grown or both

Off-color diamonds that are brownish or yellowish can be treated to modify their color. Manufacturers typically use one or both of two different processes:

  • High-pressure, high-temperature (HPHT) annealing can change some diamonds to yellow.
  • Artificial irradiation with subsequent heating (annealing) above about 500°C can be used to induce a deep yellow color in a diamond.

In both cases, the treatment is considered permanent under normal conditions of wear and care. Non-permanent treatments, like coatings, are also possible. All else being equal, diamonds that have not been treated are more expensive than diamonds that have been treated. Legally, the seller must disclose any treatments. GIA can detect these treatments, and it identifies them in the GIA Colored Diamond Grading Report. It also laser inscribes “HPHT PROCESSED” or “IRRADIATED” on the girdle of diamonds treated by either of these methods.

A 22.27 ct Fancy Vivid yellow emerald cut diamond that was artificially irradiated and annealed.

This 22.27 ct Fancy Vivid yellow emerald cut diamond was identified as artificially irradiated and annealed. Treated diamonds of this size and this attractively saturated color are rare. Photo: Sood OIl (Judy) Chia/GIA

Synthetic yellow diamonds – with properties that match their natural counterparts – are also being manufactured. The first synthetic diamonds were grown by HPHT processes that mimic the high-pressure, high-temperature conditions of natural diamond formation in the earth. Today, chemical vapor deposition (CVD) is another common method whereby synthetic diamonds are grown in an apparatus that uses high temperatures and low pressures in a vacuum chamber. The CVD process involves heating a mixture of a hydrocarbon gas (such as methane) and hydrogen, which releases carbon atoms that then settle onto the cooler, typically square-shaped seed plate of natural or, more likely, synthetic diamond. With both techniques, subsequent treatments may be used to change the color of the original crystal.

GIA can detect synthetic diamonds grown using either HPHT or CVD, and it issues distinctive reports for these synthetic or lab-grown diamonds. The GIA Synthetic Colored Diamond Grading Report offers the same information as the GIA Colored Diamond Grading Report issued for a natural diamond (see below), but it provides a more general description of the color and clarity. For additional disclosure and identification, GIA laser inscribes the diamond’s girdle with the stone’s unique report number and a statement that it is laboratory grown. The report itself looks markedly different from those issued for natural diamonds.

A 0.40 ct square-shaped diamond grown using the CVD process.

This 0.40 ct square-shaped diamond was grown using the CVD process. Photo: Sood OIl (Judy) Chia/GIA

 

Make sure GIA grades the diamond in your yellow diamond engagement ring

A yellow diamond engagement ring is a symbol of your love. It’s also a significant emotional and financial investment. So you’ll want to make sure the diamond is graded by a trusted, unbiased lab like GIA. GIA’s meticulous grading process involves testing to determine whether the diamond is natural or lab grown and to identify any known treatments used to enhance its appearance.

Highly trained colored-diamond graders observe the diamond face-up using controlled lighting in a specially designed viewing box that eliminates distractions and shields the stone from external light. These specialists determine the diamond’s characteristic color based on a combination of its size, shape, faceting arrangement and color. They then bracket the diamond using side-by-side comparisons under the same lighting conditions with two or more color references. On the basis of these comparisons, they select one of 27 hues (such as orangy yellow, yellow or greenish yellow) and assign a specific “fancy” grade based on the hue’s tone and saturation.

A GIA Colored Diamond Grading Report provides a full quality assessment of a colored diamond including the color grade, color origin (natural or treated), carat weight, clarity and a plotting diagram of its clarity characteristics. As an optional service, a full-color image of the diamond may also be included.

A GIA Colored Diamond Grading Report.

A GIA Colored Diamond Grading Report is your assurance that your yellow diamond is a natural diamond, graded to GIA’s exacting standards. It also provides full disclosure of any known treatments discovered during the grading process. Photo: GIA

A 2.03 ct Fancy Vivid yellow cushion cut diamond set in platinum.

If you’re looking for a unique engagement ring, this 2.03 ct Fancy Vivid yellow cushion cut diamond set in platinum will surely stand out. Courtesy: EraGem.com

 

A yellow diamond engagement ring is rare because yellow diamonds are rare

When you wear a yellow diamond engagement ring, you’ll have something unusual on your finger. In the early 2000s, for example, yellow diamonds represented only 2.4% of all diamonds submitted to GIA for various grading reports over the course of a single year. If unearthing a diamond is noteworthy, then discovering a yellow diamond is like finding a golden needle in a haystack.

Still yearning for a yellow diamond engagement ring? Dig a little deeper to learn more about yellow diamonds.

If you’re shopping for a diamond engagement ring, you need to know about what diamond color is if you want to understand quality and how diamonds are valued. If you are curious about what colors diamonds come in and how color grade impacts value, check out our seven essential things about diamond color you should know.

In this blog we cover:

  1. Diamond value is based (in part) on the absence of color.
  2. A diamond’s color grade should be determined by a grading laboratory.
  3. Colored diamonds are graded and valued differently from colorless diamonds.
  4. Treatments can improve diamond color.
  5. Diamond fluorescence has little to no impact on diamond color.
  6. Engagement ring settings can influence the perception of diamond color.
  7. To be sure of a diamond’s color, get a GIA grading report.

1. Diamond value is based (in part) on the absence of color

Diamond color is important: Most diamonds used in engagement rings are near-colorless with hints of yellow or brown. All things being equal, the more colorless a diamond is, the rarer it is, and this rarity will be reflected in its price.

GIA D-to-Z diamond color scale.

The GIA D-to-Z Color Scale allows for precise measurement of diamond color. Illustration: GIA

GIA’s D-to-Z Color Scale is used to measure the degree of colorlessness of a diamond. The letter “D” represents a colorless diamond, with each following letter representing a diamond that has slightly more yellow or brown.

GIA organizes diamond color into five groups:

  • Colorless (D-F): The most rare, and therefore the most valuable
  • Near-colorless (G-J): Color is often unnoticeable except by trained graders
  • Faint (K-M): Color is still difficult to see by the untrained eye
  • Very Light (N-R): Subtle color can be seen in larger stones by an untrained eye
  • Light (S-Z): Color can be seen in stones of different sizes. The diamonds appear slightly yellow or brown but do not have sufficient color to be considered a “fancy” colored diamond
GIA D-to-Z diamond color scale showing diamonds at either end of the grading spectrum.

When diamonds at either end of the grading spectrum are placed side by side, it is easy to see the differences in diamond color. Photo: GIA

2. A diamond’s color grade should be determined by a grading laboratory

The distinctions between diamond color grades can be so subtle that they are undetectable to the untrained eye. But they do make a very big difference in diamond price. That’s why determining a diamond’s color grade is best left to a gemological laboratory, like GIA, that has the expertise and processes to ensure objective, unbiased color grading.

In working to evaluate what color a diamond is, GIA graders follow a strict protocol that dictates the type of lighting and neutral background used, as well as precisely how the diamond should be held and viewed during the assessment. A color grade is determined by comparing the diamond to masterstones – a set of color-comparison diamonds of known position on the GIA D-to-Z color grading scale – when all are placed table down in a grading tray. This viewing position reduces the complex appearance of a faceted colorless to near-colorless diamond when viewed face up.

A 6.75 carat round brilliant cut diamond engagement ring featuring a diamond melee halo and band.

One look at this 6.75 carat (ct), F-color, SI-clarity round brilliant and you’ll know why diamonds are the universal symbol of love. Courtesy: 1stdibs.com

3. Colored diamonds are graded and valued differently from colorless diamonds

Diamond color is arguably the most important factor in colored diamonds. Some common colors that diamonds come in are yellow, brown, pink, red, blue, orange, purple, green, gray or black. This does not include diamonds in the normal color range that are slightly yellowish, slightly brownish or slightly grayish. When the color is natural, the diamonds are called fancy-color diamonds, fancy diamonds or fancies.

Colored diamonds come in a rainbow of hues.

Colored diamonds come in a rainbow of hues. Photo: Robert and Orasa Weldon/GIA

GIA grades colored diamonds differently from colorless diamonds. Unlike GIA’s D-to-Z grading system for colorless to light yellow diamonds, which is based on the absence of color when the diamond is viewed table down, the grading system for colored diamonds is based on the presence of color when the diamond is viewed face up. Terms used by GIA to describe colored diamonds include: Faint, Very Light, Light, Fancy Light, Fancy, Fancy Dark, Fancy Intense, Fancy Deep and Fancy Vivid.

What to look for in colored diamonds? In general, the more color a colored diamond has, the better. Fancy Deep and Fancy Vivid diamonds, for example, have more color than Fancy Light diamonds—and are usually more valuable. However, tone is also important: For example, a diamond that is extremely dark (Fancy Dark) may be less desirable than a lighter stone graded Fancy Intense.

A 3.66 ct Fancy Yellow diamond engagement ring with two halos containing 0.37 carats of yellow diamonds and 1.50 carats of colorless diamonds.

Colored diamonds can be far more expensive than colorless diamonds. Here a 3.66 ct Fancy Yellow glows like a ray of sunshine. Two halos encircle it: the inner containing 0.37 carats of yellow diamonds; the outer, 1.50 carats of colorless diamonds. Courtesy: 1stdibs.com

Fancy-color diamonds are, for the most part, far rarer than diamonds in the D-to-Z color range. Some experts estimate that only two percent of total rough diamond production is fancy colored. Since rarity influences price, it’s not surprising that spectacular blue, pink, green, orange and other colored diamonds can sell for millions of dollars at auction.

The Pink Star ring, which sold at a Sotheby’s auction for $71 million, contains a 59.60 ct Fancy Vivid pink diamond graded by GIA.

The GIA-graded Fancy Vivid pink 59.60 ct Pink Star diamond sold for $71 million at the April 4, 2017 Sotheby’s auction in Hong Kong. Courtesy: Sotheby’s

4. Treatments can improve diamond color

Diamond color can be altered by treatments. All else being equal, diamonds that have not been treated are more expensive than diamonds that have been treated. Legally, the seller must disclose any treatments. If you are aware what diamond color is, it’s easier to understand how they have been treated. 

High pressure, high temperature (HPHT) processing is perhaps the most common technique used to alter, enhance or remove color. HPHT treatment can change some brown diamonds into colorless ones or into other colors like yellow, greenish yellow or green. This process is also associated with treated pink, blue and orange-yellow diamonds. The resulting color is considered permanent, but HPHT treatment should always be disclosed.

Annealing is another process that uses controlled heating and cooling to change the color of a gem material, especially after irradiation. Irradiating a diamond or coating it are other methods used to enhance a diamond’s color.

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A 6.61 ct Fancy yellow brown diamond (left) before annealing and the same diamond (right), graded L (faint yellow) after annealing.

Before HPHT annealing to remove color, this 6.61 ct diamond was a Fancy yellow brown (left). After annealing (right), GIA graded the diamond an L (faint yellow). Photo: Robert Weldon/GIA

5. Diamond fluorescence has little to no impact on diamond color

Diamond fluorescence is visible light temporarily emitted by some diamonds when they are exposed to ultraviolet (UV) rays from the sun, fluorescent lamps or other sources. This emitted light can display various colors (often blue in diamonds), intensities (faint to very strong) and distribution patterns. When the light source is removed, the fluorescence is no longer visible.

Many in the diamond trade believe that strong blue fluorescence can make a light yellow diamond look closer to colorless when exposed to a UV source such as sunlight. Blue and yellow are color opposites and tend to cancel each other out, so blue fluorescence masks the yellow color. In rare cases, some diamonds with extremely strong fluorescence may appear slightly hazy or oily. Fewer than 0.2% of the fluorescent diamonds submitted to GIA exhibit this effect.

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A group of seven diamonds shown under daylight-equivalent illumination (left) and exposed to long-wave UV irradiation (right).

The same group of seven diamonds is shown here under daylight-equivalent illumination (left) and when exposed to long-wave UV irradiation (right). Photos: Kevin Schumacher/GIA

To answer questions from consumers and the trade about the impact of fluorescence on diamond color in the D-to-Z range, GIA conducted extensive observer testing. Here’s what its researchers found: “For the average observer, meant to represent the jewelry buying public, no systematic effects of fluorescence were detected [on the face-up appearance of the groups of diamonds]. Even the experienced observers did not consistently agree on the effects of fluorescence from one stone to the next.” As a result, GIA considers diamond fluorescence to be an identifying characteristic, not a grading factor – meaning, it has little to no impact on what color the diamond is.

6. Engagement ring settings can influence the perception of diamond color

Diamonds are highly reflective – their facets are essentially an arrangement of tiny mirrors reflecting light and the surroundings. So it should come as no surprise that the color of a ring’s prongs and shank can influence the color you see in the diamond. A white metal like platinum or white gold can emphasize the absence of color in a diamond that is colorless or near-colorless, while a gold band might make a diamond lower on the D-to-Z scale appear more yellow.

Learn more about how metal affects a diamond’s color appearance.

A 8.03 carat D color marquise cut diamond engagement ring set in platinum, flanked by two tapered baguettes weighing 0.72 carats.

The 8.03 ct marquise cut diamond in this engagement ring is D color. It is flanked by two tapered baguettes weighing a total of 0.72 carats. The platinum band and prongs highlight the beauty of the diamond. Courtesy: 1stdibs.com

7. To be sure of a diamond’s color, get a GIA grading report

A GIA Diamond Grading Report and GIA Diamond Origin Report provides an in-depth assessment of a diamond’s quality based on the 4Cs: diamond color, clarity, cut and carat weight. A report not only contains an objective color grade, but it also discloses other identifying characteristics like fluorescence, as well as any treatments detected. Learn what diamond color information is included in a GIA report.

An engagement ring is profoundly intimate and symbolic – it represents your love and commitment. A GIA Diamond Grading Report lets you make this most important purchase with peace of mind.

Now that you understand  what diamond color is and  its importance, here are 12 tips for buying an engagement ring.

Lead image courtesy of 1stdibs.com

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