Travels in India (Tavernier) 87.1.5

87.1.5

The Indians are unable to give the stones so lively a polish as we give them in Europe ; and this, I believe, is due to the fact that their wheel does not run so smoothly as ours. For, being made of steel, in order to grind it on the emery, of which it has need every twenty-four hours, it has to be taken off the tree, and it cannot be replaced so as to run as evenly as it should do. If they possessed the iron wheel as we do, for which one does not require emery but the file, it not being necessary to remove it from the tree in order to file it, they could give the stones a better polish than they do. I have stated that it is necessary to rub the wheel with emery or to file it every twenty-four hours, and it is desirable that it should be done every twelve hours if the workman is not lazy. For when the stone has run a certain time the part of the wheel where it has pressed becomes polished like a mirror, and if the place be not roughened by emery or the file, the powder does not stick to it. When it remains one does more work in one hour than in two when there is not any on the wheel. Although a particular diamond may be by nature hard, having, so to speak, a kind of knot, such as is seen in wood, the Indian diamond-cutters would not hesitate to cut such a stone, although our diamond-cutters in Europe would experience great difficulty in doing so, and as a general rule would be unwilling to undertake it; but one pays the Indians something extra for their trouble.