DIAMOND INDUSTRY, a most import ant and far-reaching department of national and international commerce, which is spreading and increasing, year by year, especially in the United States. The diamond has been a precious stone procured with difficulty, treasured up with jealous care, and sought after by the rich and magnificent for ages. Diamonds are also indispensable for instruments employed in some of the manufacturing and industrial arts. A consideration of the diamond industry must include an account of the mining, polishing, importation and sale of this gem. The dis tribution of diamonds in the geological forma tions of the world, their mining, etc., has been dwelt upon under the article DIAMOND (q.v.). It remains to point out some recent industrial facts of importance, with regard to the separa tion of diamonds from the concentrates, which remain when the diamentiferous earth has been washed, after being brought to the surface at i Kimberley; their importation to this country, and their artificial manufacture. In mining diamonds, it was necessary until recently to go very carefully over the concentrates to pick out the garnets and many other foreign sub stances until nothing remained but the rough diamonds. This is a slow and laborious opera tion, but it has been an essential part of the mining industry until it was superseded by a discovery made a while ago. The discoverer was Mr. Fred Kersten, one of the employees in the sorting room. His discovery was acci dental. A rough diamond and a garnet hap pened to be lying on a small board on the bench where he was working. He happened to pick up one end of the board when the garnet glided off but the diamond remained. Kertsen found th.it there was a coating of grease on the board Which had retained the diamond, while the garnet slipped off. He procured a wider board, coated one side of it with grease and dumped a few handfuls of concentrates on it. Then he found that by holding the board in a slightly inclined position and vibrating it, all the con centrates except the diamonds moved to the lower end and fell off while the diamonds re mained in place. Then he invented a machine by which his discovery might be utilized. The invention was an entire success. All the gar
nets and other minerals that are not wanted pass over the surface of the table while every diamond, large or small, is retained The entire work is now done by machinery, and both the young . inventor and the owners of the diamond mines are profiting by the new labor saving device. The United States is a very large purchaser of diamonds. One-third of the entire amount of cut stones is owned in this country. The importations are increasing.
More than $49,529,845 worth of diamonds and precious stones were brought into the United States in 1912-13 according to the statis tics of the Department of Commerce and Labor. This is the largest importation of diamonds and precious stones in a single year; since that date there has been a falling off, due to the war. Prior to 1887 the total had seldom, if ever, reached $10,000,000 per annum; from 1::7 to 1893 the total gradually moved upward until it reached $16,000,000; then it rapidly fell to p,sookoo in 1894, $7,500,000 in 1895, $6,750,000 in 1896, and $2,500,000 in the fiscal year 1897. In 1898 the total increased to nearly $9,000,000, in 1899 to over $14,000,000, in 1901 to $20,000,000, in 1902 to $23,000,000, and in 1903 it was about $30,000 000, making the total for the year 1903 not only more than in any preceding year, but 50 per cent in excess of 1901, double the figures in 1899, and more than six times the average during the period 1894-97.
The rapid growth in the importation of dia monds, while it suggests general prosperity, also seems to indicate the development of a comparatively new industry in the United States — the cutting of diamonds. The total . importations of diamonds alone in the 12 months ended with June 1910 amounted to $39,812,214, and of other precious stones $7,987, W. Of the $39,812,214 worth of diamonds imiSorted, $10,232,604 were uncut diamonds; this total of vo,000,000 of uncut diamonds is a large increase compared with the importations of un cut diamonds in preceding years. However, in 1913-14 the importation of diamonds fell to a total of $25314,787, of which $8,314,688 were uncut. In 1914-15 the importation was still less, due to war conditions.