Discover the Most Exceptional 4 Carat Diamonds: Type IIa Diamonds
Go beyond the 4Cs, learn more about Type IIa diamonds if you are in-market for a 4 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 the 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 4 Carat Diamonds Sold at Sotheby's
Sotheby's regularly sells impressive Type IIa 4 carat diamonds set as rings, pendants and earrings. A ring set with a Type IIa 4 carat diamond is the most popular with collectors and buyers. Take a closer look at rare Type IIa 4 carat diamonds sold at Sotheby's.
Emerald Cut 4.38 Carat Type IIa Diamond $120,000
In 2024, Sotheby's sold a emerald cut 4.38 carat, D color, Flawless, Type IIa diamond for almost $120,000. An emerald cut diamond is an excellent shape for really showcasing the special attributes of a Type IIa diamond.
Harry Winston Pear Shaped 4.04 Carat Diamond Type IIa $144,600
In 2024, Sotheby's sold a Harry Winston pear shaped 4.04 carat, D color, VVS1 clarity Type IIa diamond for $144,000. This very special Harry Winston pendant is also set with 0.95 carats of diamonds F-G color and VVS-VS clarity. While Type IIa diamonds are most often set in rings, a diamond pendant is another way to highlight an extra special 4 carat diamond.
Emerald Cut 4.02 Carat Diamond Type IIa $160,000
In 2022, Sotheby's sold an emerald cut 4.02 carat, D color, Internally Flawless, Type IIa diamond for about $160,000. The center diamond is also described as having excellent polish and symmetry.
Round Brilliant Diamond Studs 4.22 and 4.08 Carats Diamond Type IIa $445,000
In 2023, Sotheby's sold a pair of round brilliant diamond studs, 4.22 and 4.08 carats, D color, flawless, Type IIa for $445,000. Both diamonds are also characterized as having excellent polish and symmetry.
Type IIa 4 Carat Diamond Price
Prices for Type IIa 4 carat diamond can vary widely but prices generally start at around $100,000 but can exceed $200,000 for a white diamond depending on the brand and exact diamond characteristics. Sotheby's recommends only purchasing a Type IIa 4 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 4 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 4 Carat Diamond at Sotheby's
Once you have decided on a Type IIa 4 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 4 carat diamonds. Sotheby's can also source a Type IIa 4 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 of a Type IIa 4 carat diamond. Given the rarity of 4 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 auctions in New York, London, Switzerland, Paris, and Hong Kong.
- Contact a Salon Associate in New York, Zurich or Hong Kong to schedule an appointment.
- Speak to Jewelry Specialist about selling a Type IIa 4 carat diamond.
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