Not all diamonds are created equal. Beneath their seemingly identical sparkle lies a hidden classification system that determines rarity, value, and quality. Here is everything Edmonton buyers need to know before they invest.
The Hidden Classification System Every Edmonton Diamond Buyer Should Know
When most people shop for a diamond, they think about the 4 Cs: cut, colour, clarity, and carat. These are critical, but they only tell half the story. There is another, far less talked-about classification that gemologists use to categorise every single diamond in the world: diamond type.
Diamond type refers to the chemical composition of the stone itself, specifically the presence or absence of nitrogen and boron atoms within its carbon lattice. This invisible difference is what separates an ordinary diamond from one of the rarest gems on Earth, and it is the reason why two diamonds with identical 4 C grades can carry wildly different price tags.
At Design Jewellers in Edmonton, we have been working with diamonds since 1980. In this guide, we break down the four diamond types, explain why Type IIa diamonds command such a premium, and help you understand exactly what you are buying.
What Is Diamond Type and Why Does It Matter?
A diamond is composed almost entirely of carbon atoms arranged in a tight crystalline structure. However, during formation deep within the Earth's mantle, trace impurities can become trapped inside the carbon lattice. The two most common impurities are nitrogen and boron, and the way these atoms are arranged determines the diamond's type.
This classification was first developed by physicists in the 1930s, who noticed that diamonds absorbed light differently depending on their chemical makeup. Today, gemological laboratories use spectroscopy to identify diamond type as part of their advanced grading reports.
Why Edmonton Buyers Should Care
Most jewellery stores in Alberta will not mention diamond type because 98% of diamonds on the market are Type Ia. The remaining 2%, which includes Types Ib, IIa, and IIb, are significantly rarer and often command premium prices. Knowing the difference can save you money on a comparable stone, or help you justify the investment in a truly exceptional one.
The Four Diamond Types Explained
| Type | Composition | Rarity | Typical Colour |
|---|---|---|---|
| Type Ia | Nitrogen in clusters | ~98% of natural diamonds | Near-colourless to faint yellow |
| Type Ib | Nitrogen in isolated atoms | Less than 0.1% of natural diamonds | Intense yellow, orange, or brown |
| Type IIa | Almost no nitrogen | 1 to 2% of natural diamonds | Exceptional colourless, or fancy pink, brown |
| Type IIb | Boron present, no nitrogen | Less than 0.1% of natural diamonds | Blue or grey |
Type Ia Diamonds: The Standard of the Industry
Type Ia diamonds make up roughly 98% of all natural diamonds mined today. They contain nitrogen atoms arranged in small clusters of two, three, or four within the carbon lattice. These nitrogen clusters absorb light in the blue range of the spectrum, which is why most Type Ia diamonds have a faint yellow or brown tint.
This is the standard diamond you will see in nearly every engagement ring, eternity band, and pendant on the market. When a Type Ia diamond is graded D, E, or F on the colour scale, it means the nitrogen clusters are present in such low concentrations that the human eye cannot detect any colour. These near-colourless Type Ia stones are exceptional and command higher prices, but they still fall within the most common diamond category.
If you are buying a diamond in Edmonton today, there is a 98% chance it is Type Ia, regardless of price point.
Type Ia Round Brilliant, the most common diamond category
Type Ib Diamonds: The Source of Fancy Yellows
Type Ib diamonds are far rarer than Type Ia, accounting for less than 0.1% of all natural diamonds. The difference is structural: instead of being clustered together, the nitrogen atoms in a Type Ib diamond are scattered individually throughout the carbon lattice. These isolated nitrogen atoms absorb a much wider range of light, producing intense yellow, orange, or brown colours.
Type Ib diamonds are responsible for the famous "canary yellow" diamonds and many of the warm-toned fancy colour diamonds collectors prize. The Allnatt Diamond, a 101-carat fancy vivid yellow stone, is a classic example of a Type Ib diamond.
Investment Note
Fancy yellow Type Ib diamonds have steadily appreciated in value over the past two decades. A natural fancy vivid yellow diamond of one carat can sell for two to five times the price of a comparable colourless Type Ia stone of the same weight and clarity.
Fancy Vivid Yellow Type Ib Diamond
Type IIa Diamonds: The Rarest and Most Coveted
Now we arrive at the diamond type that drives connoisseurs, collectors, and serious buyers in Edmonton and around the world: Type IIa. These diamonds make up only 1 to 2% of natural diamonds and are defined by the near-complete absence of nitrogen impurities. With no nitrogen to absorb light, Type IIa diamonds achieve a level of purity and brilliance that other diamonds simply cannot match.
The most famous diamonds in the world are almost all Type IIa. The Cullinan, the Koh-i-Noor, the Lesedi La Rona, and the Graff Lesotho Promise are all Type IIa. When royalty commissions a diamond, when an auction house presents a record-breaking stone, when a museum acquires a heritage piece, Type IIa is almost always involved.
Near-zero nitrogen content. The carbon lattice is exceptionally clean, allowing maximum light transmission.
Type IIa diamonds transmit and reflect light more efficiently than any other type. They appear visibly whiter and brighter.
Type IIa stones consistently break auction records. Many command 20 to 50% more than comparable Type Ia diamonds.
Type IIa Diamond, only 1-2% of natural diamonds achieve this purity
Why Type IIa Diamonds Cost So Much More
If you have ever wondered why two D-colour, VVS1-clarity diamonds of identical size can have a price difference of thousands of dollars, the answer is almost always diamond type. Here are the five reasons Type IIa commands its premium.
1. Geological Rarity
Type IIa diamonds form under conditions of extreme heat and pressure deep within the Earth's mantle, where ambient nitrogen is essentially absent. These conditions are extraordinarily rare, which is why only 1 to 2% of all natural diamonds ever discovered are Type IIa. Compare that to gold, which is rare enough to make headlines when prices rise, and you start to understand the geological scarcity at play.
2. Superior Optical Properties
Nitrogen atoms in Type Ia diamonds slightly absorb light, especially in the blue spectrum. Type IIa diamonds, with virtually no nitrogen, allow light to pass through and reflect with greater efficiency. This is not subtle. To a trained eye, a Type IIa D-colour diamond appears visibly whiter and brighter than a Type Ia diamond of the same grade. This optical superiority is one of the main reasons collectors are willing to pay a premium.
3. Historical and Cultural Provenance
Every major historical diamond, the kind that ends up in royal collections, world-class museums, or Sotheby's catalogues, is Type IIa. The Cullinan, the Koh-i-Noor, the Lesedi La Rona, the Centenary, the Oppenheimer Blue, and the Graff Lesotho Promise are all classified as Type IIa. This historical pedigree creates a powerful cultural premium that has elevated Type IIa to almost mythological status in the diamond world.
4. Source of the Highest Clarity Grades
The cleaner the carbon lattice, the fewer inclusions and structural imperfections. Type IIa diamonds, by virtue of their chemical purity, are statistically more likely to achieve top clarity grades like Flawless (FL) and Internally Flawless (IF). When you see a high-end engagement ring at a top jeweller listing FL or IF clarity, there is a strong probability that stone is Type IIa.
5. Investment-Grade Asset Status
Over the past 30 years, Type IIa diamonds have shown stronger price appreciation than any other diamond category. They are widely considered investment-grade assets, which means buyers pay a premium not only for the stone itself but also for its long-term value retention. For high-net-worth individuals in Edmonton, Calgary, Vancouver, and Toronto, Type IIa is often part of a broader portfolio strategy alongside fine art, rare coins, and prestige watches.
Type IIb Diamonds: The Origin of Natural Blues
The final category is Type IIb, which represents less than 0.1% of all natural diamonds. These diamonds contain almost no nitrogen, but they do contain trace amounts of boron. Boron atoms absorb red and yellow light, leaving the diamond with a distinctive blue or greyish-blue hue. Type IIb diamonds are also unique in that they are the only natural diamonds capable of conducting electricity, a quirk of their boron content.
The Hope Diamond, perhaps the most famous diamond in the world, is a Type IIb. So is the Oppenheimer Blue, which sold at auction in 2016 for over 57 million USD, setting a record at the time. Blue diamonds remain among the most valuable gems on Earth.
Natural Blue Type IIb Diamond — Hope Diamond Family
Are Lab-Grown Diamonds Classified the Same Way?
Yes, but with a twist. Lab-grown diamonds are also classified into Types Ia, Ib, IIa, and IIb based on the same chemical principles. However, the production method used to grow the diamond has a significant influence on which type is produced.
HPHT (High Pressure High Temperature) diamonds, which mimic natural mantle conditions, are most often Type Ib or IIa. CVD (Chemical Vapour Deposition) diamonds, which are grown atom by atom in a vacuum chamber, are most often Type IIa.
This means that, ironically, the rarest natural diamond category (Type IIa, only 1 to 2% of natural stones) is the most common type among lab-grown diamonds. This is one reason why many lab-grown diamonds appear so brilliantly white and bright. It also explains why some buyers consider lab-grown Type IIa an excellent value proposition.
Edmonton Buyer's Tip
If brilliance and whiteness are your top priorities and budget is a consideration, a lab-grown Type IIa diamond can deliver visually stunning results at 60 to 75% less than a natural Type IIa stone. At Design Jewellers, we are happy to show you both options side by side so you can see the difference for yourself.
Natural Type IIa Diamond
Lab-Grown Type IIa Diamond
How to Know What Type of Diamond You Are Buying
Standard jewellery store sales staff are often unable to tell you the type of a diamond, because this information is rarely covered by typical grading reports. At Design Jewellers, we make it simple. Here is how to make sure you know exactly what you are getting.
Our certified team can professionally grade and appraise your diamond on location. We assess colour, clarity, cut, carat, and provide insight into the stone's quality, all without sending it anywhere.
If you specifically want a GIA-certified diamond, we can source one for you with the certificate already in hand. No shipping delays, no risk, no extra cost on your end.
Diamond Types FAQ, Edmonton
What is the most common diamond type?
Why are Type IIa diamonds so expensive?
Can the human eye tell the difference between diamond types?
Are lab-grown diamonds usually Type IIa?
Does diamond type affect the value of older or estate jewellery?
What is the rarest diamond type?
Where can I get a diamond appraised in Edmonton?
Why Edmonton Diamond Buyers Trust Design Jewellers
Five decades of evaluating, cutting, and setting diamonds for Edmonton clients. Generations of expertise in one location.
We tell you exactly what you are buying. Diamond type, grading details, and origin disclosed for every stone.
Once you have chosen your diamond, our goldsmiths design and craft the setting on-site at West Edmonton Mall.
Design Jewellers Workshop, West Edmonton Mall, Since 1980
Find Your Perfect Diamond in Edmonton
Visit our studio at West Edmonton Mall. Our experts will walk you through diamond types, the 4 Cs, and help you find the right stone for your budget and your story. No pressure, no rush.
