THE CULLINAN DIAMOND.

Wairarapa Age, Volume XXXI, Issue 3054, 26 November 1908, Page 3

THE CULLINAN DIAMOND.

It is said that there has been a great deal of secrecy about the cutting and polishing of the great Cullinan diamond, presented to King Edward by th/e Iranavaal, but the United States Consul at Amsterdam has managed to obtain some interesting farts about the processes. It was first necessary to cleave the great gem in two places, in order to remove two very bad flaws. This was done by first making an incision in the stone with a diamond-cutting saw to the depth of one-half to threequarters of an inch, following the grain, as all diamonds have a grain, just as wood has. Before this cleaving operations were carried out, crystal models were made and clefr, in order to ascertain what would happen when the same operation was performed on the real stoie. When the* incision had been made the cleaver inserted into the slit a specially constructed knife-blade of the finest steel, and struck it a hard blow with a thick steel rod, cutting the stone in twain exactly at the point where it was intended that it should be cut. Sometimes such an operation causes a diamond to fly into ,a great number of pieces. Then came the polishing, a long process. To give an idea of the hardness of diamonds, it may be interesting to state that the disc on which this diamond is being polished, which is made of cast-iron and steel, revolves at a rate of 2.400 revolutions per minute. The diamond is pressed down on this disc, which is liberally supplied with a mixture of diamond dust and oil, by weights of 15 to 25 pounds, and the disc will constantly turn from 7 a.m. to 9 p.m.. including Sundays, for ten to eleven month before the polishing operation will be completed. According to a Reuter message from Amsterdam two months ago, the stone was first divided into t vo main and several smaller pieces. The smaller of the two main pieces had been cut and polished, the result bsing a circular bluish-white brilliant of 330 carats of peerless beauty and purity. Before being cut, this stone weighed 1,000 carats, which gives a good idea of what cutting and polishing mean.