240 SYSTEMATIC DESCRIPTION OF PRECIOUS STONES 



art that greater precision in the arrangement of the facets could he attained. Owing 

 to irregularity in cutting, the play of prismatic colours in table- and point-stones was 

 often scarcely observable at all, and the stones cut after Berquen's method offered a great 

 contrast in this particular. 



Among the first and most famous diamonds cut by L. van Berquen are said to have 

 been those in the possession of Charles the Bold, Duke of Burgundy, some of which were 

 lost at the time of his defeat by the Swiss. Certain of these stones are probably still at the 

 present day in the form in which they left Berquen's hands, and they bear witness to the 

 high degree of perfection to which this artist had attained. According to Schrauf, the 

 cutting of the "Florentine" (Plate XI., Fig. 10, a, b), and of the " Sancy " diamonds 

 (Fig. 11, a, h), was the work of van Berquen ; they are cut in the briolette or pendeloqiie 

 form, a form which van Berquen was the first to adopt. 



This particular form of cutting was not often copied, at the present time it is quite 

 unused and is never shown by recently cut stones. The different varieties of the rose or 

 rosette form of cutting (Plate IV., Figs. 1-7), which were introduced in the sixteenth 

 century (about 1520), on the contrary grew quickly into favour, and at the present day are 

 in general use and frequently seen. This form of cutting is most advantageous for thin 

 and flat stones, since it involves but little waste of material and at the same time permits 

 the full display of the lustre of the stone. It is, however, inferior to certain other forms of 

 cutting in that it fails to develop to the fullest extent possible the beautiful play of colours 

 so characteristic of a cleverly cut diamond. 



The rose form was in vogue for about a century, and was then largely superseded by 

 the most perfect form of cutting yet devised, namely by the brilliant form. This form was 

 invented in the middle of the seventeenth century, and the idea is said to have originated 

 with Cardinal Mazarin. The stones first cut in this form were double-cut brilliants 

 (Plate II., Fig. 1, «, 6, c), and had on the upper part sixteen facets besides the table. At 

 the end of the seventeenth century the triple-cut brilliant (Fig. 3, a, b, c,), with thirty-two 

 facets on the upper part, was introduced by Vincent Peruzzi of Venice. This form of 

 cutting, which is still more favourable for the display of the optical properties of the stone, 

 is in use at the present day, with no alteration except that the size of the facets is more 

 equalised, as shown in Fig. 4, a, b, c, of the same plate. The various forms of cutting 

 which have subsequently come into use do not differ in any essential respect from those 

 already described. The star-cut, for example, of M. Caire (Plate III., Fig. \,a,b, c), by 

 means of a slight modification, combines an economy in the rough material, with no 

 inferiority in the display of the optical qualities of the stone. 



The loss of material involved in the cutting of a stone in the brilliant form is very 

 considerable, sometimes amounting to one-third, one-half, or to an even greater proportion 

 of the rough stone. The " Regent," for example, which is the most perfect brilliant known, 

 weighed in the rough 410 carats, while its weight after cutting was only 136| carats, or 

 only one-third as much. The " Koh-i-noor," as cut in India, weighed ISGyV carats, and 

 after re-cutting in England, 106yV carats ; again, the "Star of the South" weighed in the 

 rough 254^ carats, and as a brilliant 125 carats. The beautiful play of colours obtained 

 by the use of this form of cutting more than compensates for the waste of rough material ; 

 in no other form is this character brought out so prominently, and a good brilliant with a 

 fine play of colours, though small, is more highly prized than a larger stone cut in an 

 inferior form, and consequently with a less fine play of colours. 



The brilliant is always so mounted in its setting that the broad facet or table is turned 

 towards the observer. Only rarely, in cases in which the stone has faults to be concealed, 



