カリナン（アフリカの星）は世界最大のダイヤモンド

The largest natural diamond ever found on Earth is named Cullinan. It was discovered in a mine in South Africa on January 25, 1905. The stone weighed 3106.75 carats (621.35 grams). It was named after the mine’s owner, Thomas Major Cullinan.

図1.カリナン・ダイヤモンド

最大のダイヤモンドの歴史

History says that the diamond was found by accident. Mine manager Frederick Wells went for his evening inspection of the Premier Mine in the Transvaal and noticed a flash of light overhead. The manager decided that one of his employees was playing a joke and stuck a shard of glass into the vault of the mine. With a penknife, he picked up the “fake” and pulled out a diamond that he was surprised to see. The largest diamond in the world. The crystal was about 10 centimeters long, 6 centimeters wide and 7 centimeters high. Moreover, it turned out that the stone had exceptional clarity. The color of the diamond was whitish-blue.

After examining the stone, experts concluded that it was not a single crystal, but a piece of an even larger stone. This led to the active development of the diamond mining industry. But, alas, until now the “mother” mineral has never been found.

Fig. 2. Frederick Welsh and Thomas Cullinan with a diamond

From the owner of the mine Thomas Cullinan the diamond was bought by the Transvaal government for 150,000 pounds. It was then decided to present the stone to King Edward VII of England: in this way the country wanted to express its gratitude to the Crown for recognizing the constitution of the Transvaal. The gift was decided by vote. But the king could refuse. To the delight of the people of the Transvaal, Edward VII, on the advice of Winston Churchill, agreed to accept the gift.

In 1905, the stone was transported to England. Officially, it was sent by ship with special honors and guards from Scotland Yard. However, in reality it turned out that the ship and the solemn ceremony of sending Cullinan was just a stage for diversion. In fact, the diamond was sent by registered postal parcel. Royal Mail did not fail: the diamond arrived safely in Great Britain.

In 1907, it was presented to Edward VII on his 66th birthday. During the reception a guarantee was given that “this great and unique diamond will be preserved and protected among the other historic stones that make up the Crown’s heritage”.

From diamond to diamonds

The cutting of the Cullinan was entrusted to I. J. Asscher & Co, an Amsterdam-based company of hereditary diamond cutters. The diamond was studied for several months: unfortunately, a number of flaws were found. And in the center there was a dark spot surrounded by a light area, which spoke of an internal tension in the stone. It was impossible to cut it entirely. It was decided to break the stone into several pieces.

Fig 3. Joseph Asher breaks the Cullinan diamond

The work was carried out by the owner himself I. J. Asscher & Co. In February 1908, the stone was split into 2 pieces and then into smaller pieces based on the existing structure. This resulted in 9 large stones and 96 smaller stones. One part of 69.5 carats was left untreated. The larger ones were given their own names: from Cullinan I to Cullinan IX. All of them are the property of the English Crown.

Cullinan I

The largest of the Cullinan I diamonds also bears the name Great Star of Africa. Its weight is 530.2 carats. The stone has a pear-shaped cut with 76 facets. By order of Edward VII, Cullinan I was embedded in the top of the royal scepter. If desired, it can be removed from the scepter and worn as a brooch. Today the sceptre with Cullinan I is on display in the Tower.

Until 1990, the Cullinan I was the largest diamond in the world, but it was pushed off the pedestal by the Golden Jubilee at 545.67 carats. However, to this day, Cullinan I is still the largest diamond with a clarity of D according to the international classification (colorless).

Figure 4. Cullinan I

Cullinan II

The second largest Cullinan II weighs 317.4 carats and is called the “Little Star of Africa”. The cut of Cullinan II is a cushion. It is set on the rim of the Crown of the British Empire. Like the sceptre with Cullinan I it is on display in the Tower.

Fig 5. Cullinan II in the Crown of the British Empire

Cullinan III and Cullinan IV

The third largest diamond from the Cullinan family is cut in a pear shape. It weighs 94.4 carats. Together with Cullinan IV (a 63.6 carat cushion-cut square diamond), they were set on the crown of Queen Mary, wife of George V.

Mary wore this crown during the coronation of George V. After – the stones were replaced with replicas and the two Cullinans were combined into a pendant brooch. The pendant was subsequently inherited by Elizabeth II.

Fig 6. Brooch-pendant from Cullinan III and Cullinan IV

Cullinan V

The fifth Cullinan inherited a romantic heart-shaped cut. The weight is relatively light at 18.8 carats. The diamond is used as the center stone of a brooch that is part of the Cambridge and Delhi Durbar Parure. The brooch can be removed and mounted on Queen Mary’s crown.

Fig 7. Brooch with Cullinan V

Cullinan VI and Cullinan VIII

The 11.5 carat marquise-cut stone was given by Edward VII to his wife Alexandra, who adorned her tiara with it. It was later inherited by Queen Mary.

At that time, Mary already owned the Cullinan VIII: a 6.8-carat emerald-cut diamond. Mary decided to combine the two stones into a brooch and pendant. Together they bear the name Cullinan VI & VIII Brooch. The Cullinan VIII can be removed and used in the Cambridge and Delhi Durbar Parure if required.

Fig 8. Cullinan VI & VIII Brooch

Cullinan VII

Cullinan VII has a weight of 8.8 carats and is faceted in a “marquis” shape. It is a pendant on a platinum Delhi Durbar necklace consisting of emeralds and diamonds. This necklace is part of the Cambridge and Delhi Durbar Parure.

Fig 9. Cullinan VII wearing the Delhi Durbar necklace

Cullinan IX.

The ninth and smallest of the Cullinan weighs 4.4 carats and has an oval pendeloque cut. It is set in a ring.

Figure 10: Ring with Cullinan IX

As was the case over a century ago, all diamonds from the Cullinan family are in the possession of the English Crown. No valuation of the stones has been made. They are all believed to be priceless.