Fig. 45.—Rose
Cut (top view).
A few more years passed away, and at length at the close of the seventeenth century diamond came by its own when Vincenzio Peruzzi, a Venetian, introduced the brilliant form of cutting, and revealed for the first time its amazing ‘fire.’ Except for minor changes this form remains to this day the standard style for the shape of diamond, and the word brilliant is commonly employed to denote diamond cut in this way. So obviously and markedly superior is the style to all others that upon its discovery the owners of large roses had them re-cut as brilliants despite the loss in weight necessitated by the change.
Fig. 46.—Rose
Cut (side view).
The brilliant form is derived from the old table by increasing the number of facets and slightly altering the angles pertaining to the natural octahedron. In a perfect brilliant (Figs. 47–49) there are altogether 58 facets, 33 above and 25 below the girdle, as the edge separating the upper and lower portions of the stone is termed, which are arranged in the following manner. Eight star-facets, triangular in shape, immediately surround the large table-facet. Next come four large templets or bezels, quadrilateral in form, arranged in pairs on opposite sides of the table-facet, the four quoins or lozenges, similar in shape, coming intermediately between them; in modern practice, however, these two sets are identical in shape and size, and there are consequently eight facets of the same kind instead of two sets of four. The eight cross or skew facets and the eight skill facets, in both sets the shape being triangular, form the boundary of the girdle; modern brilliants usually have instead sixteen facets of the same shape and size. The above 33 facets lie above the girdle and form the crown of the stone. Immediately opposite and parallel to the table is the tiny culet. Next to the latter come the four large pavilion facets with the four quoins intermediately between them, both sets being five-sided but nearly quadrilateral in shape; these again are usually combined into eight facets of the same size. Eight cross facets and eight skill facets, both sets, like those in the crown, being triangular in shape, form the lower side of the girdle; these also are generally united into a set of sixteen similar facets. These 25 facets which lie below the girdle comprise the ‘pavilion,’ or base of the stone. In a regular stone properly cut a templet is nearly parallel to a pavilion, and an upper to a lower cross facet. The contour of the girdle is usually circular, but occasionally assumes less symmetrical shapes, as for instance in drop-stones or pendeloques, and the facets are at the same time distorted. The number of facets may with advantage be increased in the case of large stones. An additional set of eight star facets is often placed round the culet, the total number then being 66. It may be mentioned that the largest stone cut from the Cullinan has the exceptional number of 74 facets.
Fig. 47.—Brilliant Cut (top view).
Fig. 48.—Brilliant Cut (base view).
