The art of polishing the diamond was discovered by man at an earlier age than history has generally ascribed to it. Positive evidence, however, is wanting as to exact dates; and the proof is chiefly presumptive. However, there is no doubt but that it was far anterior to the times when Berquen announced his improvements on the process. We are quite willing to admit that the process of abrading the diamond against diamond was really discovered by the native of Bruges; but we cannot entertain the idea that the Hindoos were too stupid to pulverize the diamond and use its powder in polishing the gems. The natives had made use of powdered corundum in the earliest days, and it is preposterous not to admit they pulverized the diamond also.

Most of the gems of antiquity, whether rubies or diamonds, are cut rudely; and often, with the latter gem, the natural faces of the crystal are alone polished. Tavernier found that the native Hindoos polished the natural faces of the crystal if it was clear, and covered the flawed and the defective with facets to disguise them. And so common was this practice, that the traveller was always suspicious of the quality of the stone, whenever it was offered to him cut in this manner.

The improvement with many of these diamonds is so slight, that we consider the fact to be one of the reasons why certain natural crystals, like those in the crown and clasp of Charlemagne, for instance, were left in their rough state; the advantage derived from cutting not being equal to the time and labor expended.

It is true that we have no direct evidence of the cutting of the diamond in ancient times, and those that have descended to us from undoubted early Roman periods are in the shape of natural crystals; but still there is indirect testimony bearing in favor of the view.

The ancient gem engravers were wont to use splinters of broken diamonds in their labors upon various kinds of gems; and they probably powdered the adamas, as well as varieties of corundum, for the purpose of polishing the hard stones. Scarcity of the mineral, rather than ignorance of its properties, may have prevented its general use.

Janon de St. Laurent, in his work on engraving tools, maintains that the ancient instruments for the purpose of cutting gems were the same as the modern; and not only the wheel was used, but diamond dust was also employed in the process. There is no doubt that the wheel and other tools were in use in Asia for a long period before their adoption by the nations on the Mediterranean. So far as we know, Persia was the birthplace of gem engraving. Why are there not more examples of polished diamonds, if the process is so ancient? the reader may ask. We may in part answer this question by saying, that the process of cutting regular facets on the gems was not early known, or the custom adopted; and, the polishing being so difficult, that the lapidaries were content to polish the natural faces only. Polished crystals of diamonds of this character have descended to us from early times, and other examples are to be seen in ancient jewels. So little beauty was obtained by this polishing, that not much was gained in the vast labor required; and the native crystals were often used without any aid from the lapidary. We may see them in their rough crystalline forms in the crowns of the Gothic princes, the Iron Crown of Italy, and the ornaments of Charlemagne, besides other relics of ancient and even mediæval times.

This custom of using the rough gems prevailed to some extent in recent times; and De Laet states that as late as the middle of the seventeenth century rough spinels were preferred to the cut for ornamentation. However, we will briefly allude to one or two instances in history, which lead the reader to infer that the diamond received a definite polish at an early day. Chrysostom, an authentic writer of the fourth century, in describing the magnificence of the Greek emperors at Byzantium, mentions the dazzling splendor of the diamonds scintillating by agitation. If the historian does not use this description for the gems in general, we may infer that the diamonds had been polished; since the unpolished stones do not exhibit much, if any, play of the prismatic hues. The maxim, “diamond cut diamond,” is of ancient origin, and may perhaps be referred to the saying in vogue among the Greeks as early as the seventh century, “that for the purpose of cutting diamonds, a diamond was most effectual.”

The accounts of the Oriental historians concerning the fêtes of Timour in the fourteenth century, where diamonds were showered in profusion upon the guests, leave no doubts as to the art of polishing the gem as early as that period.

The inventory of the joyaux belonging to the Duc d’Anjou, in 1360, shows that diamonds were then cut, although rudely. It makes special mention of several diamonds, and one in particular set in a reliquary, and cut in escutcheon. Other polished diamonds are described in the account given of the splendid entertainment given at the Louvre, by the Duke of Burgundy, to the King and Court of France.

There is also evidence to prove that diamond lapidaries were at work in Paris, when Berquen came to reside there. However, it was not until 1475, after Berquen returned to his native city, Bruges, that the mode of polishing diamonds by direct abrasion became known in Europe. And when Charles the Bold intrusted the three famous gems to his skill, and rewarded him with 3,000 ducats for his labor, the name of Berquen became famous and widespread throughout Europe.

Nearly two centuries after this success, Cardinal Mazarin attempted to establish the business of diamond-cutting in Paris, and confided to the lapidaries he had invited to reside there, twelve of the finest diamonds belonging to the Crown to be recut. These gems, from their beauty, and the circumstance of cutting, were called the twelve Mazarins. History has neglected to record the fate of these magnificent gems save one. In the inventory of the French jewels in 1791, there is the solitary description, “the tenth Mazarin.” The others have disappeared.

The Cardinal made every attempt to establish the favorite project on a firm basis; but they were in vain; for the Dutch marine had complete control of most of the exports of India, and decided in favor of Amsterdam. Moreover, the establishment of the diamond trade in Holland was one of the indirect results of the revocation of the Edict of Nantes, and it was controlled by Israelite refugees from France. The business gradually languished at Paris, and of the seventy-five diamond-cutters of Mazarin’s industry, but five were left in 1775; and soon after this, in spite of individual efforts and influences, it ceased altogether. Even at the recent period of 1852, Paris did not possess a single diamond-cutter. At this time M. Philippe resolved to make the attempt to revive the good intentions of Mazarin, and has thus far succeeded well. But, in spite of all the English and French opposition, the diamond trade is still controlled by the Amsterdam Jews, several thousand of whom are engaged in the business of cutting the stones.

Diamond-cutting was also practised to some extent in London during the last century and the early part of this; but concerning it we have learned but few particulars. It was conducted on strict mathematical principles, however; and the gems cut during this time in London are eagerly sought for by amateurs, under the name of the “Old English Style.” The brilliants of Ralph Potter, cut at the commencement of this century, are by far the finest exponents of the art as well as of the natural powers of the gem. Since the discovery of the African mines the London establishments have been actively engaged, and we also learn that branches of the business have been located in other cities of England.

The process of diamond-cutting is a very simple matter to those acquainted with the nature of the gem. To cut the facets, two stones are cemented on two sticks and rubbed against each other until a facet is cut; then the position of one of the stones is changed, and another flat surface cut. The process is thus continued until the gem is faceted all over, at the expense, however, of the other stone, which does most of the cutting. After the facets are cut, and a definite form given to the stone, the gem is placed in the hands of the polisher, who fastens it in solder, and then places it upon a small steel disk which revolves horizontally with a rapidity of 1,500 to 3,000 times a minute. This disk is moistened with diamond powder mixed with oil, and one facet is polished at a time. The diamond-cutting proper is a rapid operation; but the polishing is slow and tedious. One cutter can generally furnish sufficient work for four or five polishers.

There are a number of forms adopted by the lapidaries for these gems, but the two principal ones are the brilliant and the rose. The first pattern, which was invented in Europe in the seventeenth century, is perhaps the best of all to call forth the powers of the gem. The second is of unknown age, and was practised by the Hindoos in ancient times. It affords the largest beams of light for the weight, but it lacks in colored reflections when compared with the brilliant.

For the perfection of the rainbow play of hues, it is essential that the facets of the superior and inferior parts of the stone should correspond in exact proportions and at fixed distances, so as to multiply the reflections and refractions, and produce the colors of the prismatic spectrum. Therefore the perfect cutting of the diamond is a mathematical problem, governed by rigid laws.

All limpid and white gems must be cut according to this rule, but in case of colored stones the case is far different; for perfection of color is to be attained, and brilliancy is a secondary thought. Therefore a fine ruby or sapphire may be decidedly thin in form, and yet be a gem of great beauty and value. It is very rare we obtain the full perfection of brilliancy and color in the colored gems; for generally the depth of the finest hues prevents a display of the refractive powers of the stone.

The process of rifting diamonds by splitting them in their cleavage planes was known long ago to the Hindoos; but, strange to say, it was forgotten by modern lapidaries until revived by Wollaston not many years ago. By this means masses of the crystal may be removed to escape a flaw or remove a spot, and yet preserve material that may be utilized, and which would have been lost by the process of grinding away the exterior.

Some diamonds of the spheroidal form are deficient in cleavage planes, and are quite impracticable for cutting; and the fact of the impossibility of polishing them is sufficient proof of their peculiar origin, and that their form is not due to aqueous action.

Others, known as bort, seem to be of concentric arrangement, as though crystallization radiated from the centre; and it is very difficult to polish them. The Hindoos avail themselves of this natural cleavage, and form table diamonds by adroitly striking along one of the planes of the stone with a sharp-edged tool, thereby separating the layers of the gem as the slate is rifted by the miner.

The operation, which seems so simple, really requires considerable skill and much of that acquired instinct or tact which is best exhibited by our Western Indians, who chip, with marvellous rapidity and certainty, a glass bottle into symmetrical arrow-heads. This method of reducing diamonds by cleavage was early known to the Hindoos, and is mentioned by Tavernier in an unmistakable manner in his published travels.

The process of reduction by this means is very rapidly accomplished by the skilful workman. At a glance he ascertains the direction of the laminæ, which remind one of the layers of the onion, and then cuts a small notch with another diamond in the place he selects. In this minute rift he places the edge of his blunt steel knife, and, tapping the back of it with a light iron rod, the diamond is split with perfect ease. By this process flaws and imperfections in the external layers of the stone are removed without delay. In reducing the natural diamond to a regular form much of its substance is lost, and sometimes as much as one half of the weight of the stone. This loss, however, depends greatly upon the natural form of the crystal. The perfect octahedrons lose but one fifth of their weight when transformed into the shape of the brilliant; but the rhombohedrons lose over one third in taking the same form.

The following will give the reader an idea of the losses of the rough stones when converted into fine gems. However, it must be remembered that these great stones are generally of irregular shape and are rarely of fine crystalline forms. The Mogul weighed in the rough 780¹⁄₂ karats, but was reduced in cutting to 279⁹⁄₁₆ karats. The Regent weighed 410 karats, reduced to 136¹⁴⁄₁₆ karats. The Koh-i-noor weighed 186¹⁄₂ karats, reduced to 102¹⁄₂. L’Etoile du Sud, 254¹⁄₂ karats, reduced to 124⁴⁄₁₆.

The process of cutting diamonds of large size is always attended with risk, and is necessarily a costly operation. The Regent cost in cutting $25,000, and occupied two years’ time. The Star of the South, which was cut by Coster, occupied but ninety days, and the Koh-i-noor only thirty-eight working days. This great feat in diamond-cutting was performed by the ablest of the Holland lapidaries, with the aid of steam power. Although the time expended was less than forty days, yet the cost of cutting is said to have been $40,000, which sum was lessened by the sale of the rifted fragments.

The Oriental lapidaries, destitute of mechanical appliances of any considerable aid, consumed years in cutting some of the paragons of India. This condition of affairs will explain the reason why the Armenian lapidaries asked the immense sum of $80,000 to cut the slab of diamond weighing 130 karats, which was captured by the Sultan of Persia at Coocha, in 1832.

The process of diamond-cutting has within a few years been established in the United States, and is due to the energy and superior inventive talent of Mr. Henry D. Morse, of Boston. This gentleman conceived the idea of arranging a machine for the cutting and polishing of these gems, to enable the American jewellers to have their work performed at home, instead of sending it to Europe.

While engaged in perfecting his appliances, chance threw in his way an itinerant vendor of porcelain, who had in former years served as laborer in the diamond ateliers of Amsterdam. The sight of the rough gems and the apparatus recalled to the Jew the scenes of his youth, and awakened a desire of renewing his former occupation; and he offered to perform the part of diamond-cutter. But, as the process was carefully considered, it was discovered that the Jew could only cut the facets of the diamond, and the art of the subsequent polishing he did not understand. It seemed strange that an artisan who possessed the rare ability to tell at a glance how large a gem the stone would cut, how to avoid internal imperfections, and how to take advantage of its cleavage planes, could not polish the facets after he had cut them. But such was the fact; for the two processes of cutting and polishing are widely different, and require separate instruction. However, the deficiency was soon supplied by an acquaintance, who was induced to leave Holland and act as polisher in the American diamond adventure.

The establishment was now complete, but the business was at first confined to recutting and repolishing gems that had been damaged by long use or accident. The inventive genius of Mr. Morse made several important changes in the machinery required by the lapidary, and displaced the rude and cumbersome apparatus of the old system. At first but two or three men were employed; but after the discovery of the South African diamond mines, the rough gems imported to this country soon furnished material for a more extensive establishment than was at first contemplated; and so the workshop was enlarged, and the workmen increased, until twenty-four polishing wheels were put in operation by steam power, and a force of thirty persons employed in the various parts of the process. At first none but foreigners were employed in the labor; but Mr. Morse believed that American ingenuity could master all the difficulties of the process, and finally succeeded in educating a corps of workmen who soon proved to be far superior to any of the artisans imported from the diamond-cutting establishments of Amsterdam. Now the atelier of Mr. Morse may be considered as essentially American both in its artists and its arrangements.

Many fine gems of large size have been polished by Mr. Morse, and among them four of the great weight of fifty karats each. And very recently he has ventured to attempt the cutting of a great diamond from South Africa, weighing one hundred and twenty-five karats. The operation was a successful one, and after three and a half months’ labor a beautiful gem of seventy-seven karats weight was obtained, which is greatly admired by amateurs and experts, not only on account of the rare beauty and perfection of the mineral itself, but also as a remarkable specimen of workmanship in shaping its present form.

The process of cutting the diamond is divided at Amsterdam into several distinct branches, and workmen are educated to perform one part, but not another. Thus the cleaving, the cutting, and the polishing have special operators, who become expert in performing well the parts assigned to them without attempting the others.

This ceremony and care adopted by the Jews has undoubtedly produced skilful workmen; but we see no reason why all the parts may not be perfectly acquired by an intelligent mechanic. The art of cleavage, however, requires tact, and ought to include some knowledge of mineralogy.

For the particulars of the art of diamond-cutting, we will refer our readers to the interesting chapters by Jeffries, Mawe, and Barbot; but we will, however, briefly mention some of the forms adopted for the diamond, and how they are produced.

The table and the rose patterns were the first regular forms adopted by the lapidaries. The first was simply the top of the stone ground flat with a corresponding flat bottom of less area, with its four upper and lower sides parallel to each other. As the light passed through the stone without much refraction, the beauty of the mineral was not developed by this pattern.

It has been stated that the rose shape was invented in Paris under the auspices of Cardinal Mazarin, but Tavernier describes the diamonds of Aurungzeb of India as being of the rose-cut. Therefore we must give a more ancient date to the pattern than Mazarin’s day. The form of the rose-cut is simply that of a hemisphere covered with small facets. Its flattened base is therefore admirably adapted for incrustation work, and the foil on which it is generally set serves as a refracting mirror for the entering rays of light.

The rose pattern has several names which indicate the number of facets which they may bear. If it has but twelve or less facets it is called an Antwerp rose; if but eighteen or twenty it is a semi-Holland, and a Holland rose if it bears twenty-four facets. At the present time these gems are not in much demand, unless for incrustation work, for which they are superior both in effect and in adaptability to the surface of the object to be ornamented.

The form which appears to exhibit the splendors of the gem to the best advantage is that known as the brilliant, and is rightly named from its effects. It was discovered in Italy in the latter part of the seventeenth century by Peruzzi of Venice, which city was then one of the chief gem marts of the world. The conclusions which led to the adoption of the shape were derived from experiments upon colored stones. This form of the brilliant is that of the ancient deep table modified by receiving thirty-two facets above and twenty-four below its girdle. The great relative depth of the gem, aided by the numerous facets of the sides, appears to increase the natural refractive power of the stone by confining, as it were, the rays of light inside of it.

Another pattern, called the brilliolette, shows the beautiful qualities of the gem to great advantage. It is formed like two rose diamonds joined together at the base; or may be flattened and elongated like the almond, and faceted all over with small facets. This is the form of the Sancy, and should have been given to the Koh-i-noor and the Star of the South. The Austrian yellow diamond is of this pattern, and was probably cut in India, but when and where is still a mystery. And it is thought that the famous twelve Mazarins were also cut after this shape.

The star pattern, which was invented by Caire, is but little used at the present time.