Discover Type IIa Diamonds, the Most Exceptional 10 Carat Diamonds
Go beyond the 4Cs, learn more about Type IIa diamonds if you are in-market for a 10 carat diamond.
History of Type IIa Diamonds
The Golconda region of India has been associated with the highest quality diamonds since the 4th Century BC. Golconda diamonds have historically been known for their exceptional clarity and colorlessness, but the technology to classify Type IIa diamonds wasn't formalized until the 1960s. Scientists finally had the technology to detect trace elements including nitrogen and boron in diamonds. Chemical classifications helped gemologists and jewelers to better understand the chemical properties of diamonds. Today Type IIa diamonds are also mined in other parts of the world including South Africa, Lesotho, Botswana, Angola, Zimbabwe and Canada. The mines in Galconda and Southern Africa continue to be the most important sources of Type IIa diamonds.
What is a Type IIa Diamond
About 95% of diamonds are Type Ia and contain trace amounts of nitrogen. Most diamond jewelry is made from Type Ia diamonds. Type Ib diamonds are often associated with intense canary yellow diamonds and are often used for jewelry. Type II diamonds are much rarer than Type I diamonds and have fewer inclusions and higher clarity than the more common Type I diamonds.
Type IIa diamonds are the purest form of diamonds with no measurable nitrogen or boron impurities. These diamonds are often colorless but can also be found in rare colors like pink, brown or blue. These are extremely rare and comprise less and 2% of all mined diamonds. These diamonds are formed under high-pressure and high-temperature conditions which can give the diamond higher clarity and brilliance. Gemologists describe Type IIa diamonds as having a stunning pure and clean visual appearance, almost like water or magical especially when the diamond is 10 carats or larger.
Type IIb diamonds contain boron which give them blue or grayish-blue color. Unlike other diamonds, Type IIb are semiconductors and can conduct electricity and are even rarer than Type IIa diamonds. The Hope Diamond is an example of a famous Type IIb diamond.
Famous Type IIa Golconda Diamonds
There are many famous Type IIa white diamonds from the Golconda Region including three larger than 100 carats.
Koh-i-Noor
Koh-i-Noor, meaning "Mountain of Light," is one of the most famous Type IIa diamonds from the Golconda region. It was originally 186 carats when discovered and was cut to 105.6 carats. It was discovered centuries ago and has passed through the hands of multiple rulers. Currently, it is part of the British Crown Jewels, set in the crown of Queen Elizabeth The Queen Mother.
Darya-i-Noor
Darya-i-Noor, meaning "Sea of Light" is a pale pink, table-cut diamond that has been part of the Iranian Crown Jewels. It is 182 carats and is one of the largest cut diamonds in the world. It is believed to have originated from the Golconda mines.
The Regent
The Regent is 140.64 carats and was discovered in the early 18th century. This diamond is renowned for its pure, white color and brilliant cut. It was owned by multiple royals, including French King Louis XV, and is currently on display at the Louvre in Paris. Known for its exceptional fire and brilliance, the Regent is considered one of the most beautiful diamonds in the world.
Additional Famous Type IIa Diamonds
Learn more about additional famous Type IIa diamonds over 100 carats from Africa.
Lesedi La Rona
The Lesedi La Rona means “Our Light” in Setswana, reflecting its origins and significance to the local community. It is one of the largest gem quality diamond ever discovered at 1,109 carats. This diamond was discovered in 2015 in the Karowe Mine in Botswana. The Type IIa diamond was purchased in 2017 by Laurence Graff, founder of Graff Diamonds for $53 million. After an extensive cutting and polishing process that took over a year, Graff revealed the Graff Lesedi La Rona, a 302.37-carat emerald-cut diamond. This gem is now the largest square emerald-cut diamond in the world.
Great Star of Africa
Great Star of Africa or the Cullinan I is a 530.20 carat Type IIa discovered in 1905 at the Premier Mine in South Africa. The original rough diamond weighed a record breaking 3,106 carats, making it the largest gem-quality rough diamond ever found. The Cullinan diamond is a pear shaped diamond with 74 facets and was set in the head of the Sovereign’s Sceptre with Cross, part of the British Crown Jewels. The Cullinan I remains a prominent piece of the British Crown Jewels, housed in the Tower of London.
Winston Legacy
101.73-carat, D-color, flawless, pear-shaped diamond classified as Type IIa, indicating exceptional purity and transparency. Discovered in Botswana's Jwaneng Mine, the original rough diamond weighed 236 carats. After nearly two years of meticulous cutting and polishing, it achieved its remarkable final form.
Stunning Type IIa 10 Carat Diamonds Sold at Sotheby's
Sotheby's regularly sells impressive Type IIa 10 carat diamonds set as rings, pendants and earrings. A ring set with a Type IIa 10 carat diamond is the most popular with collectors and buyers. Take a closer look at rare Type IIa 10 carat diamonds sold at Sotheby's.
Graff Type IIa 10.02 Carat Diamond $900,000
In 2024, Sotheby's sold a rare Graff 10.02 Carat diamond, D color, flawless, Type IIa for just over $900,000. The oval center diamond was flanked by two heart shaped diamonds. Graff has been known for exceptional diamonds since 1960. Graff is the the only High Jewelry brand that controls end to end production from mine to finished jewelry creation. Oval diamond rings have become much more popular with High Jewelry buyers due in part to the number of celebrities that have opted for this shape in the last five years. Prices for the highest quality oval diamonds are also often a premium to other shapes due to greater demand and difficulty sourcing this shape at 10 carats and larger.
Bvlgari Type IIa 10.01 Carat Diamond $620,000
In 2022, Sotheby's sold a Bvlgari 10.01 Carat Diamond, D Color, internally flawless, Type IIa for just over $620,000. The center cushion cut diamond had excellent polish and symmetry flanked by two pear shaped diamonds mounted in platinum. Cushion cut diamond rings don't get the same attention as emerald cut or oval, but it remains a favorite for its link to the old mine cut and vintage appeal.
Pear Shaped Type IIa 10.75 Carat Diamond $680,000
In 2021, Sotheby's sold a Pear shaped 10.75 carat diamond, D color, VVS1, Type IIa for just over $680,000. The center pear shaped diamond had excellent polish and symmetry. Pear shaped diamonds are popular for High Jewelry rings due to their unique shape that combines the best of a round and marquis diamond.
Harry Winston 10.36 Carat Oval Diamond $510,000
In 2024, Sotheby's sold a Harry Winston 10.36 Carat Diamond, D Color, VS1, Type IIa for just over $510,000. The oval center stone had excellent polish and was flanked by two pear shaped diamond shoulders. The center diamond came with a working diagram stating the clarity may be improvable after minor repolishing. The price difference for this oval 10 carat diamond compared to the Graff oval diamond 10 carat diamond is the difference in the clarity.
Tiffany & Co 10.03 Carat Hear Shaped Diamond Pendant $880,000
In 2021, Sotheby's sold a Tiffany & Co 10.03 Diamond Pendant, D Color, Flawless, Type IIa for just over $880,000. The heart shaped center diamond pendant had excellent polish and symmetry.
Type IIa 10 Carat Diamond Price
Prices for Type IIa 10 carat diamond can vary widely but prices generally start at $500,000 and can easily exceed $1 million for a white diamond. Sotheby's recommends only purchasing a Type IIa 10 carat diamond with a GIA certificate that will include the classification as Type IIa. Most diamonds that are classified as Type IIa are generally D color and Flawless or Internally Flawless clarity and have excellent polish and symmetry. In general, a Type IIa diamond is priced at a premium to a Type I diamond but the overall quality and size of the diamond all factor into the price.
Once you have decided on a 10 carat diamond, it's worth going beyond the 4Cs and considering a Type IIa diamond. In addition to the pure visual appeal of Type IIa diamonds, the rarity of these diamonds also impact the long term value in the market.
Buy and Selling a Type IIa 10 Carat Diamond at Sotheby's
Once you have decided on a Type IIa 10 carat diamond, Sotheby's has a few ways to assist with the purchase of these rare and exceptional diamonds. Sotheby's often has impressive Type IIa diamonds available at auction, including 10 carat diamonds. Sotheby's is also able you to source Type IIa 10 carat diamond for immediate purchase. Once we have your budget range and preferred shapes, we can connect with our international network of suppliers to source a few options. A salon specialist can also arrange a private viewing once a Type IIa 10 carat diamond has been sourced. Given the rarity of 10 carat Type IIa diamonds, it could take a few weeks to view a few options and flexibility on the exact shape and carat weight is suggested to have more options.
- Explore upcoming jewelry at auctions in New York, London, Switzerland, Paris, and Hong Kong.
- Speak to a Salon Associate in New York, Zurich or Hong Kong to schedule an appointment.
- Speak to Jewelry Specialist about selling a Type IIa 10 carat diamond.
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