February 08, 2021

Diamonds form hundreds of kilometers beneath the earth’s crust under tremendous heat and pressure. They are predominantly Carbon, but more than 95% of natural diamonds show traces of other elements in their composition. In fact, most certified D-Flawless diamonds are not the purest diamonds in nature. Although they exhibit the highest color and clarity grade, there are subtle, yet important, chemical and technical differences that separate these diamonds from the crème de la crème - Type IIa diamonds.

What are Type IIa Diamonds?

Type IIa diamonds are a category of diamonds that exhibit no measurable traces of nitrogen or boron in their structure. Although other diamond-types may represent a high diamond color grade (D) they contain some other non-carbon element in the crystal structure. In contrast, Type IIa diamonds often display a higher color due to their pure carbon composition.

When and by Whom were Type IIa Diamonds discovered?

In 1934, scientists Robert Robertson, John Jacob Fox, and A.E. Martin conducted proprietary experiments on diamonds and classified them into two main types: Type I and Type II. The bifurcation is largely “based on the presence or absence of nitrogen impurities.”¹ However, upon further research, diamonds were subdivided into Type Ia (1A), Type Ib (1B), Type IIa (2A), and Type IIb (2B) based on “the arrangement of nitrogen atoms [aggregated or isolated] and the occurrence of boron.”² The diamond-type “[directly relates] to color and the lattice defects” that can be “modified by treatments to change color.”³ Overall, the method to classify diamonds by type is “a convenient way to categorize [them] based on their chemical and physical properties”⁴ for researchers and gemologists. It also helps explain why two diamonds with similar weight, color, clarity, and cut grade may look different to the eye.

How do you know if a diamond is Type IIa?

The best way to know about a diamond’s type is through a gemological laboratory, such as the Gemological Institute of America (GIA). GIA offers diamond-type testing for a fee; however, the service is not recommended for majority of diamonds in the market. Type IIa diamonds are rare and accompany a supplemental Type IIa Letter with the Diamond Grading Report from GIA.

Are Type IIa diamonds really special?

Yes. Although Type IIa diamonds are pure carbon and hold a special place for researchers and gemologists, their history is more captivating to diamond collectors and aficionados. Prior to the scientific discovery and classification system by the scientists in the 1930s, Type IIa diamonds were unknowingly prevalent in the collections of kings, queens, and noblemen. Notably, many of the world’s largest and most famous diamonds – Koh-i-noor (105.60 ct.), Cullinan, Archduke Joseph (78.54 ct.), Agra Pink Diamond (41 ct.), Elizabeth Taylor Diamond (33.19 ct.), Star of the South (128 ct.), Pink Legacy (18.96 ct.), and several others – are Type IIa.

These diamonds, among other notable diamonds, originate from the world’s first diamond source – the Golconda diamond mines near Hyderabad, India.

Does a Type IIa diamond command a premium price over non-Type IIa diamonds?

Yes, but it’s nominal. Surprisingly, it may come at a price similar to a non-Type IIa diamond. Type IIa diamonds are so scarce that most diamond dealers don’t bother procuring them and overlook this distinction in their day-to-day business. In fairness, consumers are largely unaware about diamond types and rarely ask about them. However, as individuals learn more about diamond-types and their uniqueness, we expect a rise in premiums for Type IIa diamonds.

Would I recommend a Type IIa diamond?

Absolutely. I am more intrigued by the true rarity of these diamonds as compared to other diamonds that are beautiful but largely romanticized because of a remarkable marketing campaign. Diamonds are a wonderful gem, but what makes Type IIa diamond stand apart from others is their high purity and ability to exhibit a higher color than other non-Type IIa diamonds in the market.

¹ Breeding, Christopher M, and Shigley, James E. "The "Type" Classification System of Diamonds and Its Importance in Gemology." Gems & Gemology 45, no. 2 (2009): 96
² Ibid.
³ Ibid.
⁴ Ibid.

Article by Sumeet Chordia, G.G.

If you have seen a description or a gemological report of a color gemstone, such as an Emerald, Ruby, Sapphire, Tourmaline, Alexandrite, etc. which states the name of a country then you have come across an important and highly valuable piece of information — that of gemstone origin. This is not to be confused with an origin for an article of jewelry, such as “Made In …” which is often stamped with the name of the manufacturing country or its distinct hallmarks.

In this first education series, we share basic information about the history, scientific methods, famous origins, risks, and value associated with the geographic origins of gemstones so you can gain a better understanding of the subject and make an informed decision about the purchase of an important gemstone or jewelry piece.

A gemstone’s geographic origin is the country, state, or region, from where the stone is believed to have been unearthed. It does not mean the location where it was cut, polished, traded, or set in a piece of jewelry.

It’s worth noting that the geographic origin of gemstones directly impacts its value. Whether it should is a healthy discussion and one that has been going on in the industry for decades. However, for the scope of this series, we will adhere to current market trends and demands.

Before we go further it is important to understand the impact and significance of gemstone origin. As an example, a ruby from one country can be sold for hundreds of dollars-per-carat and another ruby from a different country can be sold for hundreds of thousands to millions of dollars-per-carat. This raises significant responsibilities throughout the supply and value chain, especially before it reaches the hand of the end customers who rely on absolute trust from their jeweler.

While the variation in price may come as a surprise to many we hope our educational series sheds valuable information on this topic and helps address any questions or concerns. Our goal is to build an educated community so your experience with a gemstone or jewelry purchase is thoughtful, positive, and with minimal risk.

In order to move forward, we must take a step back and dive into history and visit the 1950s in the serene town of Lucerne, Switzerland where the idea and scientific study of geographic gemstone origin was introduced and established.