Where to Buy Blue Diamonds Online

Where to Buy Blue Diamonds Online

Are you in search of the ideal online destination to purchase blue diamond jewelry? Look no further! In this guide by Learning Jewelry, we will address typical inquiries such as:

  • What factors should you consider when buying blue diamonds online?
  • Is blue diamond a suitable choice for an engagement ring?
  • How can you ensure that you’re getting a fair price?
  • What warning signs should you be aware of when making a purchase?

Best Places to Buy Blue Diamond Jewelry Online

In case you require a rapid rundown, here are my foremost recommendations for sourcing excellent sapphires from trustworthy online retailers. Each of these stores is a viable option for purchasing diamonds. Continue reading for additional details regarding each of these retailers.

What is a Blue Diamond?

Blue diamonds are a type of fancy colored diamond that occur when diamonds are exposed to particular impurities during their formation in the earth. Boron is the impurity responsible for the blue coloration in the diamond crystal.

Due to the rarity of the occurrence of boron being introduced to the crystal in the proper saturation, blue diamonds are uncommon. In some cases, blue diamonds may display a greenish or grayish tint alongside their blue hue.

The world’s most renowned blue diamond is known as the Hope Diamond. Throughout history, many of its owners have encountered misfortune, leading some to believe that the diamond is cursed. The Hope Diamond can presently be viewed at the Smithsonian Museum in Washington DC.

If you’re interested in discovering the backstory of this infamous blue diamond, be sure to watch the accompanying video below.

Genuine, untreated blue diamonds are exceptionally uncommon. However, it’s possible to obtain a natural blue diamond that has undergone heat treatment to enhance its color intensity. While lab-grown blue diamonds remain relatively expensive, they are less costly than their natural counterparts and offer superior color and clarity.

RECOMMENDED: Diamond Lab Reports to Avoid

To determine whether a blue diamond has undergone any treatment, refer to its grading report.

  1. Buying Blue Diamonds at Blue Nile

Shop at Blue Nile

Blue Nile and James Allen are often featured at the top of our guides, but today, Blue Nile claims the top spot. Among all the recommended retailers, Blue Nile offers the most extensive assortment of natural diamonds.

The store offers roughly 25 loose blue diamonds, although about half of them have a minimum weight of .5 carats. All colored and colorless diamonds at Blue Nile have been certified by GIA, which is critical when purchasing diamonds. Additionally, they are untreated, which contributes to their high pricing.

The cost of a blue diamond at Blue Nile varies. The least expensive option is a .27 carat marquise blue diamond priced at around $57,000. However, it’s essential to bear in mind that blue diamonds are naturally rare, which contributes to their high cost. The most expensive option runs approximately $370,000.

Blue Nile also offers a section dedicated to colored lab diamond jewelry, which includes blue diamonds. Under the Lightbox Jewelry section, you can select from around 20 different options for lab-created blue diamond necklaces, earrings, bracelets, and rings. These lab-grown options are significantly less expensive than natural blue diamonds.

The absence of a warranty for the ring setting is my main concern when purchasing blue diamonds from Blue Nile. While they do provide a manufacturer’s warranty for design defects, routine upkeep such as rhodium plating white gold would require an out-of-pocket expense. Nonetheless, one complimentary ring sizing is included.

Blue Nile allows for a 30-day return policy if you are dissatisfied with your blue diamond purchase. They offer round-the-clock customer service for ease of accessibility and boast a reputable history as the pioneer of online diamond retailing.

Shop at Blue Nile


  • Unenhanced blue diamonds of natural origin
  • Lab-created blue diamonds
  • Lifetime upgrade guarantee
  • Clear 360˚ visibility


  • Limited warranty from the manufacturer

Shop at Blue Nile

RECOMMENDED: Best Lab Grown Diamonds

  1. Blue Diamond Purchases at Brilliant Earth

Shop at Brilliant Earth

Brilliant Earth is a well-known name in the world of online diamond retailers, especially for their “Beyond Conflict Free” campaign. Although they comply with the Kimberley Process, unlike other retailers, Brilliant Earth can trace the origin of their diamonds, which is a big plus.

They offer natural blue diamonds, but currently have none available. However, they do have a collection of 60 lab-created blue diamonds in a wide range of shades, including midnight blue and icy blue sapphire, making them a top choice for those seeking blue diamonds.

Brilliant Earth’s 360˚ video provides an excellent view of the diamond, allowing customers to see every aspect of their diamond. They also offer a lifetime manufacturing warranty, which covers any defects in craftsmanship.

However, there is a $50 fee to assess if the issue is a defect, and if it is, the fee is refunded. Otherwise, it is used for repairs or shipping costs. Customers should be aware of this policy when seeking repairs.

Brilliant Earth’s Extended Service Plan is a paid warranty that covers routine maintenance, such as prong retipping and stone tightening, for 3 years on a sliding scale. They also offer a range of lab-created fancy vivid blue diamonds, including the one shown below.



  • Extensive collection of blue diamonds
  • Option to purchase a warranty
  • Lifetime upgrade guarantee
  • Clear and adjustable 360˚ view


  • The only maintenance plan available is a paid warranty for 3 years
  • No natural diamonds are currently available

Shop at Brilliant Earth

  1. James Allen Blue Diamond Purchases

Shop at James Allen

James Allen, which is usually a top contender on our lists, is currently ranked lower for blue diamonds due to its limited selection. Their fancy color diamond section includes lab-created fancy colored diamonds, but they only have yellow diamonds available at the moment.

Their natural blue diamond collection is also limited, with less than 10 loose blue diamonds currently available, ranging in price from $7,300 to $400,000. These untreated diamonds come with a GIA grading report and are categorized as Fancy, Fancy Intense, or Fancy Vivid.

If you purchase a blue diamond worth $30,000 or more, James Allen offers a free ring setting valued at up to $1,500 or a $1,500 discount on a more expensive setting. They also offer a lifetime warranty, which covers routine maintenance such as tightening stones, jewelry steam cleaning, and rhodium plating for white gold. However, customers are required to pay a $35 shipping fee when sending in their jewelry for repair, and resizing is only free for engagement and wedding rings.


James Allen’s blue diamond selection is limited, but they offer free ring settings or discounts for high-value purchases and a lifetime warranty for routine maintenance.


  • GIA certified diamonds
  • Lifetime warranty
  • Clear 360˚ view


  • Limited selection
  • Most diamonds are priced over $15,000

Shop at James Allen

Frequently Asked Questions About Blue Diamonds

Is a blue diamond a good choice for an engagement ring?

Yes, any diamond is a great option for an engagement ring due to its superior hardness and scratch resistance. On the Mohs scale of mineral hardness, diamonds score a perfect 10, making them the most durable mineral in the world.

mohs hardness scale

Are blue diamonds more durable than other colored diamonds?

No, blue diamonds do not have any greater durability than other colored diamonds. The level of hardness is dependent on the diamond’s structure and is not affected by color. However, a treated blue diamond can be less durable if it has been coated.

Are blue diamonds more expensive than other diamonds?

Yes, natural blue diamonds that have not been treated are extremely rare and therefore command a higher price than colorless diamonds or other fancy colored diamonds. Even small, untreated blue diamonds can cost tens of thousands of dollars. Red diamonds are the most expensive, while pink diamonds and lab-created yellow diamonds are less expensive than natural blue diamonds.

What to Look For When Buying Blue Diamonds Online

When purchasing blue diamonds online, it is essential to consider the 4Cs grading system: carat weight, cut, clarity, and color. The Gemological Institute of America developed this system to evaluate diamond quality, although gemstones typically follow the same general criteria without assigned grades.


When it comes to white or colorless diamonds, the cut is crucial as it forms the foundation of the stone and determines the brilliance and sparkle. Ideal or excellent cut grades are highly sought after in these diamonds. However, when it comes to colored diamonds, too much brilliance is not always desirable.

For blue diamonds, brilliant cuts such as round, princess, and cushion cuts are not recommended as they can detract from the color.

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According to official standards, non-round diamond shapes do not have specific cut grades like round diamonds. While round diamonds can have ideal or excellent cut grades, fancy shapes are usually categorized as Good or Very Good. However, selecting a non-round diamond shape requires paying attention to the specific proportions and measurements required for that particular shape, as each shape is unique.



The value of blue diamonds primarily depends on their color and the combination of tone, hue, and saturation. Instead of grading each factor separately, the Gemological Institute of America (GIA) considers them collectively in their grading system.

Tone refers to the lightness or darkness of the diamond, but it is not as crucial as hue and saturation. If the blue diamond is too light or too dark, the hue would be difficult to perceive. The GIA grading terms for fancy diamonds include Faint, Very Light, Light, Fancy Light, Fancy, Fancy Dark, Fancy Deep, Fancy Intense, and Fancy Vivid. Most natural blue diamonds found are rated as Fancy Light or higher.

Hue is the dominant color seen in the diamond when viewed under light. The GIA hue scale consists of red, orange, yellow, green, blue, violet, and purple. For instance, sapphires can appear green with secondary hues of either violet or green.

When selecting a fancy colored diamond, it is generally preferable to choose one with a single, solid hue. Sometimes, colored gemstones may exhibit secondary hues of other colors, which can either enhance or detract from their value.

While certain secondary hues can increase the value of a fancy diamond, most do not. For instance, purplish blue or yellowish green hues are generally considered undesirable. However, there are a few exceptions to this rule, such as with fancy brown diamonds, fancy dark blue diamonds, and grayish blue diamonds.

The saturation of a blue diamond is a crucial factor in determining its overall quality. It refers to the intensity of the hue, which can vary widely between diamonds.

For example, a Fancy Blue diamond will not appear the same as a fancy yellow diamond because the saturation is typically higher in fancy yellow diamonds. On the other hand, a Fancy Intense blue diamond may be more similar in appearance to a Fancy Yellow diamond due to its higher saturation level.


Due to their rarity, finding a natural fancy blue diamond that is eye-clean, or without visible inclusions to the naked eye, is a challenge. Although small inclusions may lower a blue diamond’s value, they should have minimal impact on clarity grading.

RECOMMENDED: Types of Diamond Inclusions

Fancy colored diamonds, like colored gemstones, are classified into types. However, the classification system is different for colored diamonds, as they are divided into Type Ia, Type IIa, Type Ib, and Type IIb.

Type Ia colored diamonds have nitrogen aggregates throughout their crystal structure, which gives them a yellowish color. As a result, fancy yellow and orange diamonds are classified as Type Ia colored diamonds.

Type IIa colored diamonds, on the other hand, have a distinct fluorescence and no visible absorption. They are free of nitrogen impurities and are extremely rare, with only 1% of all mined diamonds falling under this category. Blue diamonds are classified as Type IIa diamonds and are considered the most precious of all fancy colored diamonds.


As you are aware, untreated natural blue diamonds are extremely uncommon and expensive. Take, for instance, this fancy intense blue diamond weighing 0.43 carats from Leibish and Co. Its price exceeds $100,000!


Undoubtedly, the diamond is stunning, but its price is beyond most people’s budgets. Furthermore, a diamond of only .21 carats may not have much impact in jewelry, except as a complement.

If you desire a larger blue diamond but don’t want to spend a fortune, there are some options available to you. For instance, you may consider treated blue diamonds that have been enhanced by heat. Additionally, synthetic or lab-created blue diamonds can also reduce the cost of a blue diamond while still providing a similar look.

What are the red flags when buying blue diamonds online?

When purchasing blue diamonds online, it’s important to be aware of potential red flags. One red flag to watch out for is blue diamond simulants, which are manmade or natural gemstones that are designed to resemble blue diamonds. Cubic zirconia (CZ) is a common simulant that can be colored to resemble blue diamonds. If the title or description mentions the word “simulant,” it is not a genuine blue diamond. Another common simulant for gemstones is glass, which can be faceted to resemble genuine stones.

RECOMMENDED: Best Diamond Substitutes

Another red flag to keep in mind is that natural and untreated blue diamonds are very rare and expensive. If a blue diamond is priced too good to be true, it’s likely a fake or a lower quality stone.

Treated blue diamonds, on the other hand, are more affordable and popular in fashion jewelry. These stones are often heat-treated and may be accompanied by blue rhodium to enhance their color. Small heat-treated blue diamonds can be found in sterling silver fashion jewelry for under $200. However, lab-created blue diamonds may appear more artificial in color compared to natural blue diamonds.

What are some tips to ensure you get the best deal when purchasing blue diamonds online?

To secure the best deal when buying blue diamonds online, there are a few things to keep in mind. One crucial factor is obtaining a grading report from a trustworthy laboratory like GIA or AGS. These reports are necessary to ensure that you’re not being deceived when purchasing natural, untreated blue diamonds online.

GIA provides grading reports for both natural and lab-colored diamonds, with two options for natural diamonds: the standard colored diamond grading report and the color grading and origin report. The latter report includes information on the diamond’s origin, and it is also laser-inscribed for added security. By getting a grading report, you can be confident in your purchase and avoid being taken advantage of by unscrupulous online vendors.

Know the Treatments

It’s important to be aware of the treatments applied to synthetic or mined blue diamonds before making a purchase. If you opt for a treated diamond, find out what specific treatments it has undergone. If the treatment involved irradiation or heat to enhance its blue color, there is no need to worry about color fading.

Blue diamonds can only lose their color when subjected to temperatures exceeding 500 degrees Celsius. Nonetheless, it’s essential to inform any jeweler working on your treated blue diamond ring about its treatments. The jeweler’s torch may affect the color, so they should remove the stone before working on the metalwork.

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