722 



DIAMOND. 



Dnmond. 



Art of cut' 

 ting and 

 polishing 

 diamonds. 



The celebrated traveller, Tavernier, who visited these 

 mines, gives the following account of the process. 



" After the miners have pitched upon the place where 

 they intend to work, they level another place close by, 

 of the same extent, or else a little bigger, which they 

 enclose with a wall about two feet high ; in the bot- 

 tom of that little wall, at the distance of every two 

 feet, they make small holes to let in the water, which 

 they stop up afterwards, till they come to drain out the 

 water again. This done, their labours are preceded by 

 acts of devotion, and a very simple feast. When that 

 is over, the men fall to digging, the women and chil- 

 dren to carry the earth to the place prepared in that 

 manner, as I have already described: they dig ten, 

 twelve, and sometimes fourteen feet deep; but when 

 they come to any water, they leave off. All the earth 

 being carried into the place before mentioned, the men, 

 women, and children, with pitchers, throw the water 

 which is in the drain upon the earth, letting it soak for 

 two or three days, according to the hardness of it, till 

 it come to be a kind of batter, then they open the holes 

 in the wall to let out the water, and throw on more 

 water until all the mud is washed away, and nothing 

 left but the sand ; after that they dry it in the sim, 

 and then they winnow the sand in little winnows as 

 we winnow our corn. The small dust flies away, the 

 great remains, which they pour out again upon the 

 ground. 



The earth being thus winnowed, they spread it 

 with a kind of rake as thin as they possibly can, then 

 with a wooden instrument like a pavier's rammer, about 

 half a foot wide at the bottom, they pound the earth 

 from one end to the other two or three times over ; af- 

 ter that they winnow it again, and spreading it at one 

 end of the van, for fear of losing any of the earth, 

 they then look for the diamonds." 



Diamonds are also collected from the gravel or sand 

 of rivers. The river Gouel, near Soumelpour, in the 

 province of Bengal, in the time of Tavernier, was said 

 to be noted in this respect, and is the most ancient dia- 

 mond district in the East. In the island of Borneo, 

 diamonds are collected from the gravel and sand of the 

 river Succadan. 



The ancients were unacquainted with the art of cut- 

 ting the diamond ; and hence they used it in its natu- 

 ral, granular, or crystallised state. Even in the middle 

 ages, this art remained still unknown ; for the four 

 large diamonds that ornament the clasp of the imperial 

 mantle of Charlemagne, and which is still preserved in 

 Paris, are uncut octahedral crystals. 



The art of cutting and polishing diamonds was pro- 

 bably known to the artists of Hindostan and China at 

 a very early period. European artists, until the fif- 

 teenth century, were of opinion that it was impossible 

 to cut the diamond. Robert de Berghen, in the year 

 1 456, endeavoured to polish two diamonds, by rubbing 

 them against each other. He found, that, by this 

 means, a facet was produced on the surface of the dia- 

 monds ; and, in consequence of this hint, constructed a 

 polishing wheel, on which, by means of diamond pow- 

 der, he was enabled to cut and polish this substance in 

 the same way as other gems are wrought by emery. 

 This art has been gradually improved, particularly by 

 the Dutch and British jewellers. For a long time all 

 the finest diamonds were sent to Holland to be cut and 

 polished, owing to the real or fancied superiority of the 

 Dutch artists. Now the diamond cutters in London 

 are considered as equal to any in the world ; and we 



no longer hear of this gem being sent abroad to be cut Diamond. 

 by foreign artists, on account of any want of skill in our s — ^v^™ / 

 workmen. 



The cutting and polishing of the diamond is effected 

 in the following manner : If the rough diamond has 

 rents or flaws which must be removed, or if the figure 

 is such that it must be altered before it is regularly cut, 

 we either split or saw off the part or parts. The split- 

 ting is effected by the blow of a hammer on a small 

 chissel, placed in the direction of the folia or cleavage 

 of the diamond. The sawing is effected by means of 

 an iron wire attached to a bow ; the wire is covered 

 with diamond powder, and drawn backwards and for- 

 words, until the portion is cut off. This, however, is 

 a very tedious process, as the wire is generally cut 

 through after having been drawn across the diamond 

 five or six times, and thus requires very frequent re- 

 newal. When the diamond is in this way freed from 

 its flaws, and reduced to the proper shape, it is next 

 imbedded in a strong cement of brick dust and white 

 pitch, fixed at the end of a spindle-shaped stick about 

 a foot long, with that portion only projecting, the re- 

 moval of which is to form the facet. The facet is form- 

 ed by the friction of another diamond fixed in a stick in a 

 similar manner to the former, with one of the angles 

 projecting. In order to collect the powder and splin- 

 ters that are detached during the process, the cutting is 

 performed over a strong box, four or five inches square, 

 furnished with a false bottom, perforated with exces- 

 sively minute holes, in order to sift as it were the dust 

 from the splinters ; and also with two upright iron pegs 

 fixed on the sides for the workmen to support and 

 6teady his fingers against, while, with a sharp repeated 

 stroke, somewhat between scratching and cutting, he is 

 wearing away the diamond on that part where the fa- 

 cet is to be made. This being done, the cement is soft- 

 ened by warming it, and the position of the diamond 

 is changed, in order to bring a fresh part under the 

 action of the cutting diamond. When, in this manner, 

 all the facets have been cut upon the surface of the di- 

 amond, the cutting is completed. The next object is 

 to polish the facets, and, at the same time, to remove 

 any little inequalities that may have taken place in the 

 cutting. The polishing mill is very simple. It con- 

 sists of a circular horizontal plate of cast iron, 14- or 15 

 inches in diameter, (called a skive) suspended on a 

 spindle, and put in motion by means of a wheel 5 or 6 

 feet in diameter, and turned by an assistant. From the 

 centre to the circumference of the iron plate, are shal- 

 low grooves, formed by rubbing it in that direction 

 with a fine grained sandstone ; these grooves serve to 

 retain the mixture of oil and diamond powder with 

 which the plate is charged. In order to keep the dia- 

 mond perfectly steady while the polishing of each fa- 

 cet is going on, the following contrivance is had re- 

 course to. A copper cup, about three quarters of an 

 inch in depth and width, and furnished with a stem 

 about four inches long of thick copper wire, is filled 

 with plumbers' solder, which also projects in a conical 

 form beyond the rim of the cup ; in the apex of this 

 cone, the solder being softened by heat, the diamond i6 

 imbedded with one of the facets projecting. The stem 

 of the cup is now put into very powerful pincers, which 

 screw up with a nut and a wrench, and thus hold it 

 perfectly tight. The handles of the pincers are of 

 wood, are broad, and terminated by tAvo feet about an 

 inch high. In this position the diamond is placed on 

 the plate, the pincers resting on their legs on the wood- 



