technique of cameo shell.
The shells used to produce cameos come from the Bahamas, the Antilles and the coast of East Africa. Shells give different cameos with different colors. For example, cameos carved on Cassis madagascariensis (commonly known as "sardonic") have white figures on brown background; those of Cypraecassis rufa (aka "carnelian") have reddish more or less dark. The cameos are more valuable than those having a greater color contrast.
The first step consists in cutting the "cup" - the part of the shell that will be used - with a disc saw water cooled. The shape of the cameos to obtain, typically oval or round, is plotted on the inner surface of the "cup", which is then cut into polygonal pieces smaller. Typically, a shell of medium size can be derived only a cameo large and two small. It takes a trained eye to assess the potential of each shell, or to determine where to make the cuts. If a piece has three protrusions ("bumps") on the outer surface, for example, it may be that there is likely to affect three figures. Once cut, each piece is brought to the desired shape with a grinding wheel. Done this is fixed on a wooden stick, so as to be more easily handled, and the outermost layer is removed and irregular bringing the fragment of a shell to the right thickness. At this point the artist is inspired by the shape of the piece to choose the subject to be engraved. Track on the surface of a quick pencil sketch and begins its work.
The excess material is removed with a small milling cutter: an electric drill with an abrasive tip. Once he sketched the figure in its essential volumes starts the incision by hand with a series of sharp instruments of various sizes the said chisels. The figure is made at the right depth, right where the shell changes color and becomes dark. Hacking at different depths, the artist can give the impression that there are transparent veils. Eventually a figure full of detail stands out in relief against a dark background!
The choice of subjects is endless. Perhaps you have seen cameos with a female profile: a classic. Tiny cameos with profiles of faces or flowers are mounted on rings and earrings. Cameos larger diameter up to 7.8 cm, they are used for brooches or pendants and those engraved may be more complex: landscapes and pastoral scenes or the classical repertoire. The greatest ever, reaching up to 20 centimeters, they can be framed or mounted on pedestals. Their value depends not only on the size and materials used in the frame, but also the processing and care with which they were produced. Some are real works of art.
Since the worker oversees and must take advantage of the irregularities of the material on which works to produce the finished part, it will never be possible to mechanize the production of shell cameos and no two will ever exist exactly identical. This truly unique ornaments and fascinating: true works of art in miniature.