skip to main content
User icon simplified man
the israel diamond industry logo

HOW WAS THE LARGEST EVER ROUGH DIAMOND CUT?

A historic document tells how the Cullinan Diamond was cleaved, cut and polished
cullina diamond collection
Credit: Annabelle Robinson / Bonhams

Late last month (April 30), Bonhams put up for sale a historic document that tells the story of the cutting of the Cullinan Diamond – the largest rough ever found – into diamonds that today form part of the Crown Jewels and the collection of Queen Elizabeth II.

 

The Bonhams auction included the original documents a paste replica of the Cullinan in its original rough crystal form and two replica sets of the nine principal diamonds cut from the uncut diamond. The lot, estimated at £2,000-3,000 ($2,600-3,900), ended up beating its estimate, and sold for $27,845 after a bidding war between live, online and phone buyers.

 

 

cullinan diamonds collection
Credit: Annabelle Robinson / Bonhams

 

From Rags to Riches

 

The original manuscript copy, dated January 29, 1908, is called “Agreement for the Inspection of the Cullinan Diamond” between the representatives of King Edward VII and London diamond brokers M.J Levy & Nephews. Following the agreement, the formidable 3,106-carat diamond was cut by the Asscher Company in Amsterdam into the nine principal Cullinan Diamonds that today form part of the Crown Jewels of Great Britain.

 

The Cullinan was discovered in 1905 near Pretoria, South Africa. According to Bonhams, the stone was “so immense that it was initially thought to be a large piece of rock crystal rather than a diamond”. Named after Thomas Cullinan, chairman of the mine where it was found, the Cullinan was initially a hard sell. It was eventually sold for £150,000 (around $196,000) to the South African Transvaal Colony government in 1907. The company then gifted the diamond to King Edward VII on his 66th birthday that November “as a symbol of South Africa’s loyalty to the Crown”.

 

Following the advice given by the London diamond brokers M.J. Levy & Nephews, the cutting of the diamond was entrusted to Asscher Company in Amsterdam, which a few years earlier cut the 995.2-carat Excelsior Diamond.

 

cullinan diamonds polish history
Credit: Annabelle Robinson / Bonhams

 

The Cutting Process

 

Joseph Asscher, the “most gifted cleaver of the Asscher Company”, was given the stone. It was agreed that such a formidable stone could not be cut and shaped without splitting it first, so Asscher created a 6.5mm deep incision in the diamond over several days. He cleaved the Cullinan into two parts, weighing 1,977 carats and 1,040 carats.

 

Over the following months, these two diamonds were further polished and cut, Nine main stones were created, named Cullinan I through to Cullinan IX, as well as 96 smaller diamonds.

 

Today, the Cullinan I is the largest polished ‘white’ diamond in the world. It weighs 530.20 carats and sits atop the Sovereign’s Sceptre. Cullinan II weighs 317.40 carats and is set at the front of the Imperial State Crown, in the Tower of London.

More Articles

Buy Diamonds

Get Hot Updates