642 



PRECIOUS STONES. 



parent bodies. One of these, examined by 

 George P. Kunz. was either a cube with faces of 

 the tetrahexahedron or else a distorted trigonal 

 tris-octahedron. The others were very much 

 distorted, and two resemble the latter form, 

 which is one of the principal diamond forms, 

 and the colors were either pink or light brown. 

 From their smallness a determination of the 

 hardness could not be made, but by grinding 

 with a sapphire 4 particles of the meteorite a 

 number of minute but deep scratches on each 

 polished face of 9 different sapphires were made 

 with each piece of meteorite. These scratches 

 are characteristic of the diamond. Lazarus 

 Fletcher, of the British Museum, read a paper 

 on a meteorite which was discovered in the sub- 

 district of Youndegin, Australia, in 1884. and an- 

 nounced that he had found a new form of graph- 

 ite of cubic form, with the hardness of 2'5 and a 

 specific gravity of 2'12, to which he gave the name 

 of " cliftonite." It was examined with a J-inch 

 objective, and from its structure Mr. Fletcher 

 concluded that, while it differed from native 

 graphite, the sharpness, separateness, and com- 

 pleteness of the crystal, the brightness of the 

 faces, the delicacy of the acicular projections, 

 and especially of the obtuse, almost flat, square 

 pyramids of some of the faces, were sufficient to 

 prove that the form never had any other than its 

 present tenants ; in other words, that it was not 

 a pseudomorph. When in the cubes, the dia- 

 mond has faces not very unlike those of the 

 Youndegin crystals, and showed a similar bev- 

 eling of its edges by the rounded tetrahexedra. 



Properties of the Diamond. Considerable 

 attention has been given to the alleged power of 

 diamonds to emit light in absolute darkness. 

 William Crookes, in his experiments on the 

 phosphorescence of various colored diamonds, 

 found that those glowing pale blue had the 

 longest residual glow, followed by the yellow. 

 He was unable to detect any glow in reddish 

 diamonds. A large greenish diamond, very phos- 

 phorescent, shone almost as brightly in the phos- 

 phoroscope as out of it. Crookes says : " Next 

 to the diamond, the ruby is, perhaps, the most 

 strikingly phosphorescent stone I examined. It 

 glows with a rich full red, and a remarkable fea- 

 ture is that it is of little consequence what de- 

 gree of color the earth or stone possesses natu- 

 ally, the color of the phosphorescence being 

 nearly the same in all cases; chemically precipi- 

 tated, amorphous alumina rubies of a pale red- 

 dish yellow, and gems of the prized pigeon's- 

 blood color, glowing alike in the vacuum, thus 

 corroborating Edouard Becquerel's results on 

 the action of light on alumina and its compounds 

 in the phosphoroscope. The appearance of the 

 alumina glow in the spectroscope shows a faint 

 continuous spectrum ending in the red near the 

 line B ; then a black space, and next an in- 

 tensely brilliant and sharp red line, to which 

 nearly the whole of the intensity of the colored 

 glow is due. 



Many large diamonds, if at all imperfect or of 

 inferior color, are cleaved into smaller stones, in 

 which the poor color is less apparent, as it is 

 only the white diamonds that increase in value 

 as they are larger. 



There are about 12 cutting establishments in 

 this country, employing from 1 to 50 men each, 



and in all about 100, with salaries from $20 to 

 $50 a week. Most of the cutting is of a high 

 class, some shops being almost entirely employed 

 in recutting stones that were cut abroad. Ten 

 years ago nearly all the diamonds used in the 

 United States were purchased through brokers 

 or importers ; but, owing to the growth of the 

 diamond business and the facilities for travel, 

 many of the large retail houses now buy their 

 diamonds direct in the European markets, and 

 some have even established agencies there. In 

 1877 an international syndicate composed of 

 London, Paris, and Amsterdam jewelers, wish- 

 ing to establish a uniform value for the carat, 

 confirmed 205 milligrammes as the standard, 

 and this was generally accepted. 



Henry D. Morse, of Boston, was the first to 

 cut diamonds in this country, and the best cut- 

 ters in the United States received their training 

 under him. Besides educating young men and 

 women to his art, he showed the world that dia- 

 mond cutting, which had so long been a monop- 

 oly of the Hollanders, was degenerating in their 

 hands into a mere mechanical trade. His treat- 

 ment of the diamond gave a great stimulus to 

 the industry. Shops were opened in the United 

 States and London in consequence of his success. 

 He studied the diamond scientifically, and taught 

 his pupils that mathematical precision in cutting 

 greatly enchances the value as well as the beauty 

 of the gem. In his shop a machine for cutting 

 diamonds was invented that did away in a great 

 measure with the tediousness and inaccuracy of 

 the old manual process, and it is due to him 

 that we now have the best cutters in the world. 

 He died in Boston in January, 1888. 



The jeweling of watches in the United States 

 is estimated to require about 10,000,000 to 12.- 

 000,000 jewels a year, 5,000,000 being ruby and 

 sapphire, and 7,000,000 garnet jewels, valued at 

 about $300,000. The larger part of these are 

 imported, but the Waltham Company alone em- 

 ploys about 200 persons in the cutting of its 

 jewels. At least 15,000 carats of boart are used 

 annually for this purpose. 



Formation of the Diamond. It has been 

 suggested that the South African diamonds were 

 formed in a sort of volcanic mud ; that the ac- 

 tion was hydrothermal rather than igneous, the 

 diamonds being the result of the contact of 

 steam and magnesian mud under pressure upon 

 the carbonaceous shales. Sir Henry E. Roscoe, 

 in a paper on the diamond-bearing rocks of 

 South Africa, said he had noticed that a peculiar 

 odor, somewhat like camphor, was evolved upon 

 treating the soft blue diamond earth with hot 

 water. He powdered and digested a quantity of 

 this earth with ether, and on filtering and al- 

 lowing the ether to evaporate he obtained a 

 small quantity of a crystalline, strongly aromatic, 

 volatile body, burning easily with a smoky flame, 

 melting at 50 C. The quantity obtained was 

 too small to admit of a full investigation of its 

 composition and properties. He suggested that 

 perhaps the diamond was formed from a hydro- 

 carbon simultaneously with this aromatic body. 

 H. Carvill Lewis, in describing the genesis of 

 the diamond, said that from the De Beers mine, 

 at a depth of 600 feet, there had been sent him 

 specimens of rock that were unaltered, and 

 proved to be a peridotite containing carbona- 



