JONKER DIAMOND

Otago Daily Times, Issue 22911, 19 June 1936, Page 10

JONKER DIAMOND

FAMOUS GEM CUT WORK OF BELGIAN EXPERT. Fourth among the great diamond finds of history and until recently the largest uncut stone in the world, the famous Jonker diamond, said by experts to be unequalled in purity and potential beauty, is now in pieces. It was announced in New York last month at the offices of Harry Winston, jewel dealer, who bought the stone in London at a price rumou ed to be between 700..000 and 1,000,000 dollars, that the huge diamond had been successfully cleaved. It was the second of the great diamonds in the world’s history to bo cleaved. In 1008 the fabulous Culinah stone was split.

Newspaper reporters and photographers were invited to witness the cleaving of the diamond, but they learned on arriving that because of the delicate nature of the operation it had been performed in private.

Lazare Kaplan, a native of Belgium, regarded by experts ns the master diamond cutter of the world, explained the process. Cleaving, he said, was the first step in cutting up a large stone. The exact grain of the gem is found and a groove is cut along it with the sharp edges of other diamonds. A hard steel wedge is inserted into the groove, and with the tap of a weight the diamond is split along the grain—if the. job is properly done. A slight mistake, a false move, and the stone may splinter ifito many pieces, largely destroying its value. Since last June Mr Kaplan had been studying the grain of the Jonkqr diamond, making more than 100 plaster and 101 lead models of the stone to assist his calculations. After grooving the gem for a week he undertook the cleaving. So tense and serious a job was it that only his son, Leo, aged 23, already an expert, was present to assist. Not even Mr Winston, the owner, could be near. Drawing in a breath. Leo Kaplan placed the wedge in the groove. Mr Kaplan tapped. Ho used a specially counter* balahced weight that made the tap short and precise. As Leo looked the great stone split. “ It’s perfect, father! ” he exclaimed.

Before that, one small end, enough to make a marquise cut, had been cleaved from the diamond. The stone is no\v in three pieces. The Kaplans, relieved and happy, pasted the pieces together and went through the motions of cleaving the stone for photographers. The diamond, weighing 720 carats, wail found in January, 1034. by Jacobus Jonker in Elandsfontein, Pretoria. South Africa! It was registered as “extra bine white and pure,” and immediately took a place of great importance in the gem world because of its excellence. When it is all cleaved, cut and polished, in three months, there will be 12 stones, cut in modern fashion for a necklace. One stone will be the third largest in the world, hut it will bn of unparalleled quality, it is said. Although about 300 carats will be lost in the cutting and polishing processes. Mr Winston expressed the belief that the collection of stone*' would he worth twice that of the original. He said he would try to keep them together, if someone could afford to buy the lot.