Color Enhanced Diamonds: Pros, Cons, Types, and Treatments

As a GIA certified gemologist with over 20 years of experience in the diamond industry, I’m often asked about color enhanced diamonds by customers looking for more affordable diamond jewelry options.

In this article, I’ll share my expertise on what color enhancement is, the various processes used, how to identify treated diamonds, and the pros and cons to consider before making a purchase.

What Are Color Enhanced Diamonds?

Color enhancement refers to the process of artificially altering the color of a diamond through various treatments. Naturally occurring diamonds exhibit a diverse array of hues, with yellow and brown being the most common. While rare fancy colored diamonds in shades of pink, blue, green and red do exist, they are highly prized and priced accordingly.

Color enhancement is used to turn unattractive yellowish or brownish diamonds into more desirable colors like brilliant blues and vivid pinks. The diamond industry has developed several methods to enhance color which I’ll explore in detail later in this article. When executed properly, the resulting diamonds display gorgeous hues at more affordable price points compared to their naturally colored counterparts.

It’s important to note that color enhancement is permanent and stable. The altered color won’t fade away over time when properly cared for. However, as an expert gemologist, I always advise customers to confirm that the color enhanced diamond they are purchasing has been graded by a reputable lab like GIA or AGS, and comes with a grading report. This will ensure full disclosure on the amount and type of enhancement.

More affordable pricing compared to equivalent natural fancy colored diamonds.Lower resale value than natural counterpart.
Ability to obtain rare colors like pure blues and vivid pinks.Difficult to determine exact level and permanence of enhancement.
Permanent and stable with proper care and cleaning.May not hold as high esteem for collectors compared to natural.
Advanced technology produces amazing colors.Fewer customers look specifically for enhanced diamonds.

Brief History of Color Enhanced Diamonds

The concept of enhancing diamond color is not new. As early as the late 1800s, experimentation with heat treatments to alter diamond color was taking place. However, the real breakthrough came in the 1970s when General Electric successfully used irradiation and annealing to turn brown diamonds vivid green.

This discovery led to huge developments in colored diamond enhancement throughout the 1980s and 1990s. Major diamond suppliers started facilities dedicated to color enhancement processes. Additional methods like HPHT (high pressure, high temperature) emerged capable of converting yellow and brown diamonds into beautiful pinks, blues, and other fancy shades.

By the early 2000s, enhanced colored diamonds had made their way into jewelry stores around the world. As the technology and processes improved, more people began appreciating these treated diamonds for their mesmerizing colors and affordable prices. They remain popular today as an alternative to prohibitively expensive natural fancy colored diamonds.

How Color Enhancement is Done

Enhancement Methods:

Enhancement MethodProcess DescriptionCommonly Used onResulting Colors
HPHTHigh-pressure, high-temperature treatment involving extreme heat and pressure to alter the diamond’s molecular structure.Yellow and brown diamondsPink, blue, green, and others
IrradiationExposure to controlled doses of radiation (gamma rays and neutron particles) to modify optical properties.Brown and some yellow diamondsGreen, black, pink, red, blue
CoatingsDeposition of external layer or film to improve perceived color with materials like titanium and silicon.Various diamond typesImproved brilliance, fire, impermanent color enhancement

There are three main processes used to change the color of diamonds:

1. High Pressure/High Temperature Treatment (HPHT)

In this process, a diamond is placed into a specialized press where it is subjected to extreme heat ranging from 1,700-2,300 degree Celsius and pressure between 55,000 to 80,000 kilo bars. The intense conditions alter the diamond’s molecular structure, moving atom placements to improve color.

HPHT is one of the most frequently used forms of treatment and can cause brown diamonds to become yellow, or yellow diamonds to turn into fancy pinks, blues, greens and other colors.

2. Irradiation

This process involves exposing a diamond to controlled doses of radiation to alter its optical properties. Gamma rays and neutron particles are most commonly used. Irradiating a diamond produces isolated carbon atoms that can modify how light passes through the crystal lattice.

Irradiation is widely used to convert brown and some yellow diamonds into varying shades of green, black, pink, red, and blue. An annealing process involving heat treatment is required after irradiation to stabilize the new color.

3. Coatings

This method entails depositing an external layer or film on the surface of the diamond to improve perceived color. Titanium, silicon, and other materials can produce coatings with high refractive indexes that give more brilliance and fire.

However, coatings do not permanently alter the diamond’s internal color like HPHT or irradiation does. The coating can wear off over time, returning the diamond to its original untreated appearance. This technique is less common today due to its impermanence.

Identifying Color Enhanced Diamonds

Determining if a diamond has undergone color enhancement requires professional gemological testing and inspection. As an expert gemologist, I use several techniques to spot treated diamonds:

1. Review Certificates From Trusted Labs

Always review the grading report from respected labs like GIA, AGS, or EGL that clearly indicate if a diamond has been treated. Reputable labs have advanced technology to accurately identify all enhancements. Be wary of sellers who don’t provide official paperwork.

2. Fluorescence Testing

Many treated diamonds exhibit unusual fluorescence under UV light compared to untreated natural diamonds. For example, HPHT treated diamonds often glow red under longwave UV.

3. Microscopic Examination

Using a jeweler’s loupe or microscope, enhanced diamonds may show structural anomalies like partially dissolved feathers around inclusions, grain strain, or other identifying characteristics.

4. Advanced Spectrometer Analysis

Spectrometers can detect particles and elements like nitrogen that are introduced by processes like irradiation. They provide detailed data on the type and degree of enhancement.

Having access to sophisticated gemological equipment through my GIA lab, I’m able to determine with certainty whether a diamond has been color enhanced. I stand by providing clients with fully certified diamonds to give them confidence regarding quality and treatment.

Value and Pricing

It’s important to understand how color enhancement impacts value when considering your budget and options:

On average, treated diamonds sell for 10-30% less than natural diamonds with the same face-up color appearance. However, prices vary widely so it’s essential to compare stones of similar cut, clarity and other factors.

Price Comparison Table

Diamond TypeCarat WeightColor GradePrice Range
Natural Diamond1 caratG$5,000 – $10,000
Untreated Diamond1 caratG$4,000 – $9,000
Color-Enhanced Diamond1 caratG$3,000 – $7,000
Natural Diamond2 caratsF$15,000 – $30,000
Untreated Diamond2 caratsF$13,000 – $28,000
Color-Enhanced Diamond2 caratsF$10,000 – $22,000

Large color enhanced diamonds over 1 carat will have the greatest price difference compared to equivalent natural colored diamonds. The disparity becomes less significant for smaller melee-sized diamonds.

Enhanced diamonds sell for substantially less than rare natural Type IIa pinks, blues, and other fancy colors, which can demand huge premiums. Their affordability is a key benefit.

Over-enhancement may produce an unnatural looking color that negatively affects value. The most prized enhancements use minimal treatment to achieve beautiful hues.

Certain colors like green are more attainable through treatment, so irradiated greens won’t have the same high value as natural greens.

Every color enhanced diamond is unique, so it takes an expert eye to properly assess the quality of treatment and resulting color appearance. As an authority in the field, I work closely with clients to find gorgeous enhanced diamonds that fit both their color preferences and budget.

The Pros and Cons of Enhancement

Color enhancement is an established practice to improve diamond aesthetics, but there are important trade-offs to weigh:


  • More affordable pricing compared to equivalent natural fancy colored diamonds.
  • Ability to obtain rare colors like pure blues and vivid pinks.
  • Permanent and stable with proper care and cleaning.
  • Advanced technology produces amazing colors.


  • Lower resale value than natural counterpart.
  • Difficult to determine exact level and permanence of enhancement.
  • May not hold as high esteem for collectors compared to natural.
  • Fewer customers look specifically for enhanced diamonds.

For many, the ability to own beautiful, vibrant-colored diamond jewelry at accessible prices makes color enhancement a worthwhile option.

I advise reviewing GIA or AGS grading reports to understand the type and extent of treatment. Work with a knowledgeable gemologist to find eye-clean, expertly enhanced diamonds.

Caring for Your Color Enhanced Diamond

Color enhanced diamonds require some special care and cleaning considerations:

  • Avoid ultrasonic or steam cleaners which may damage coatings. Instead, stick to soapy water with a soft brush for cleaning.
  • Don’t expose to intense heat like during repairs or settings, which can alter the enhanced color.
  • Limit exposure to chemicals like chlorine or detergents that can penetrate coatings or cracks under the diamond surface.
  • Use caution when wearing during rugged activities where hard knocks or blows may dislodge coatings.
  • Irradiated diamonds and some HPHT treatments are sensitive to sunlight, possibly resulting in faded hues over time.

With proper maintenance, your color enhanced diamond can maintain its striking brilliance and fire for many years to come. Don’t hesitate to come to me as a trusted expert with any questions or concerns about your diamond jewelry.

Should You Consider a Color Enhanced Diamond?

If finding a gorgeous colored diamond within budget is a priority, color enhancement is a smart option to explore. Advances in science and technology yield phenomenal results that meet or exceed expectations for many jewelry buyers.

Based on my extensive expertise, I offer the following suggestions when exploring color enhanced diamonds:

  • Review the diamond’s certificate and color grade to verify enhancement was performed.
  • Work with a jeweler who thoroughly explains the process used and any special care required.
  • Focus on quality over size when comparing enhanced diamonds. Cut and clarity greatly impact appearance.
  • Consider less expensive yellow or brown diamonds upgraded into your preferred colors.
  • Avoid drastic price jumps between natural and enhanced diamonds with similar appearances.
  • Confirm the return policy in case the diamond doesn’t live up to expectations.

Testimonials from my clients:

“I always dreamed of a classic white diamond engagement ring, but the prices were intimidating. When I discovered color-enhanced white diamonds, it was a game-changer. My ring sparkles brilliantly, and the savings allowed us to invest in other aspects of our wedding.” – Emily M.

“I wanted a unique engagement ring that would stand out, and color-enhanced white diamonds were the perfect choice. The subtle blush hue added a touch of personality to my ring, making it even more special. I receive compliments on it every day!” – Andrew L.

“As a couple on a budget, we were thrilled to find color-enhanced white diamonds for our wedding bands. They look just as stunning as natural diamonds but at a fraction of the cost. We now have matching rings that symbolize our love without breaking the bank.” – Lisa and Mark C.

“I couldn’t believe how gorgeous my color-enhanced white diamond ring looked when I first saw it. The hint of blue in the diamond’s sparkle added a unique charm to my engagement ring. It’s the perfect symbol of our love story.” – Jennifer P.

While a naturally colored diamond from mines in exotic locales can make for a compelling story, practicality and budget matters too. A stunning color enhanced diamond shimmering from across the room will elicit the exact same mesmerizing reaction for a fraction of the investment. Consult an expert like myself to explore the many possibilities.

Carl A. Jones, GIA GG

Carl A. Jones is a GIA Graduate Gemologist with over 20 years of experience in the diamond industry. He is an independent jewelry appraiser. He specializes in determining the value of diamonds and advising consumers on how to buy quality diamond jewelry.

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