And you thought you had stress?

How do you cut a very large diamond?

         Very carefully.

The planning of the cutting is much more critical than  the cutting itself. It can take weeks, even months, of painstaking evaluation of the diamond crystal to determine just how and where  to strike the first cleaving blow. The goal is to have the diamond crystal split into smaller pieces. The slightest miscalculation and  the rough diamond crystal is liable to shatter into dust.

There are only about a handful of diamond-cutters who are entrusted with the larger  pieces of rough diamonds.

These cutters are  under intense pressure. 

Mr. Joseph Ascher, of Ascher Diamond Co. Amsterdam, who  was assigned the enormous task of cutting the worlds largest known diamond, (the 3601 carat Cullinan) studied the huge crystal  for about six months before deciding on exactly how and where  to cleave it.

He  had a doctor standing by at the critical moment.  Word has it he fainted after the second  attempt which fortunately was successful.

The Cullinan was named after Sir Thomas Cullinan, chairman of the fabled Premier Mine (the richest diamond mine, it yields one part diamond for every fourteen million parts of its weight in rock and soil.). The Cullinan was found in January 1905 by Fred 'Daddy'  Wells, surface manager of South Africa's Premier mine.  The South African Government bought the stone for £150,000 and presented it  to King Edward VII on his 66th birthday in 1907.

By the time Mr. Ascher was finished,  he had cut the Cullinan into nine major diamonds and ninety-six smaller ones.   At 520.20 carat, the pear-shaped Cullinan I  (also known as  "The Star of Africa") is the largest cut diamond in the world and is stashed at the Tower of London as part of the Crown Jewels, mounted in the Royal Scepter. The Cullinan II is cushion-shaped, weighs 312.40 carats and is set in the Imperial State Crown, also among the Crown Jewels.

Diamond cutting in New York gained international recognition in 1936 when Lazare Kaplan cut the 726 carat Jonker diamond (found at the Premier Mine in 1934) which, at the time, was valued at one-half million dollars.

He dedicated the better part of an entire year to scrutinizing the stone from every possible angle. If he was wrong, he could shatter the diamond crystal and render it worthless.

Kaplan disagreed with all the "expert European cutters" as to the direction of the diamond's grain. He had made up his mind and, on April 27 of 1936, he struck the cleaving knife and the Jonker fell apart, precisely as he calculated.  

A News Headline in the National Jeweler October 1994

"$20 Mil. Diamond Shatters at Cutters"

"One of the largest rough diamonds in the world shattered in a New York diamond manufacturing plant.

The 445.9 carat diamond was bought from De Beers by two brothers, for about $20 million.

It was sent to Rudolf Ehrenwalt's factory in New York to be sawn into three different stones.

But it never reached that stage. During a no-doubt heartbreaking moment, the diamond slipped

out of the hand of one of the factory workers when he was on the way to the safe. It fell and

broke into a number of pieces, making it considerably less valuable. And to make matters worse,

Lloyds of London appeared reluctant to pay the claim. The case is now in court."