The history of the discovery and cutting of the Cullinan Diamond – key facts

The Cullinan Diamond, named after Sir Thomas Cullinan, founder of the Premier Mine, is the largest gem-quality diamond ever found. Its discovery on January 26, 1905, at the Premier Mine in South Africa was purely accidental. Frederick Wells, the mine manager, noticed a huge crystal in the wall of the excavation during a routine inspection, which he initially considered worthless. However, it turned out to be a rough diamond weighing 3,106 carats (approx. 621 grams). The discovery caused a global sensation and marked the beginning of a new chapter in the history of precious stones.

Table of contents

• From mining to the British crown
• Cullinan I and II – royal diamonds
• Cutting the Cullinan Diamond – a breakthrough in jewelry technology
• Cullinan as a symbol of monarchy and luxury
• The Legacy of Cullinan

From mining to the British crown

After its extraction, the Cullinan Diamond was purchased by the Transvaal government for £150,000 and then presented to King Edward VII on his 66th birthday as a symbol of loyalty and an attempt to repair relations after the recently ended Boer Wars. On November 9, 1907, the stone arrived in Amsterdam, where it was cut and polished by the highly acclaimed Asscher brothers' workshop.

This task was entrusted to Joseph Asscher, the most outstanding diamond cutter of the time. The process was extremely risky because the diamond had internal cracks. The first cut had to be made with absolute precision so as not to destroy the priceless crystal. According to a famous anecdote, the moment was so stressful that after making the decisive cut, Joseph Asscher fainted from the tension. The process of cutting and polishing took eight months and resulted in 9 large and 96 smaller diamonds with a total weight of 1,063.65 carats.

Cullinan I and II – royal diamonds

The two largest and most famous gems created from rough crystal are the Cullinan I and Cullinan II, also known as the Great Star of Africa and the Second Star of Africa.

• The Cullinan I (Great Star of Africa), weighing 530.20 carats, is the world's largest colorless (perfect D color) cut diamond. It has been cut in a pear shape (pendeloque), and its unique feature is that it can be removed from its setting and worn as a brooch. It is permanently set in the British Sovereign's Sceptre with the Cross and, along with other crown jewels, is kept in the Tower of London.
• The Cullinan II (Second Star of Africa), weighing 317.4 carats, is a cushion-cut diamond set in the center of the Imperial State Crown, used by British monarchs during important state ceremonies, such as the opening of Parliament.

The remaining diamonds – Cullinan III, IV, V, VI, VII, VIII, and IX – vary in shape and size (from 94.4 to 4.4 carats). Many of them are in the private collection of the royal family and adorn, among other things, Queen Mary's crown and the famous brooches that were often worn by Queen Elizabeth II.

Cutting the Cullinan Diamond – a breakthrough in jewelry technology

Cutting the Cullinan diamond was one of the greatest challenges in the history of gemology. Special tools were created, and months of research into the crystal's structure preceded any work. Although the latest steam engines and grinding wheels available at the time were used for cutting and polishing, the process itself relied on master craftsmanship and experience.

The scale of this undertaking highlighted the need to develop more advanced techniques for analyzing the internal structure of stones. The challenge posed by the Cullinan inspired future generations of cutters and engineers, contributing to the development of technologies that are now standard, such as 3D computer modeling, laser scanning, and crystal stress analysis. To this day, the Cullinan remains a point of reference in gemological literature.

Cullinan as a symbol of monarchy and luxury

Thanks to its size, exceptional clarity, and remarkable origin, the Cullinan is not only a historic stone, but also a powerful symbol of the strength and continuity of the British monarchy. Its diamonds adorn the most important insignia of power, emphasizing the historical connections with King Edward VII and subsequent monarchs.

The Cullinan I and Cullinan II are an integral part of the British Crown Jewels, playing a key role in coronation ceremonies and major state events, bearing witness to the heritage and prestige of Great Britain.

The Legacy of Cullinan

Since the diamond was discovered in the Premier Mine in 1905, its history has fascinated researchers and jewelry enthusiasts alike. Today, the finest diamonds from this crystal—Cullinan I and II—remain at the heart of British royal identity, as visible symbols of history, power, and the unmatched perfection of nature, cut by the hand of a master.