A stone carved so that the design is cut into the surface and is the opposite of a cameo (carved in relief).
The origin of the engraved signet-stone can be traced right back to the Sumerian period in Mesopotamia. Seals were used in the Ancient Near East from about 3400BC for over three thousand years, however initially only relatively soft stones were used. Due to the soft nature of the material a precise, detailed image could not be produced on such a small scale. Therefore new technologies were required to carve harder, more durable materials.
Even right back at this time gemstones were prized above all other possessions and this led to a high perfection in the art of gem-cutting. These materials would have been immensely difficult to carve and engrave in such detail with the tools and materials available at the time. Therefore the engraved gemstone must have been a valued and treasured possession belonging to someone of immense importance and wealth.
The classical history of gem-engraving in Europe is known to begin in the second quarter of the sixth century BC, as this is when new materials and techniques became available to the Greek artist. The new techniques were those required to work the harder stones, mainly the use of a cutting wheel and drill, probably driven by a bow, where before figures had been cut or gouged free-hand in the soft stone. Techniques were passed down to the Romans, and the use of drills and wheel technology soon enabled the processing of harder gemstones and facilitated the production of more demanding images. A finely carved seal was practical, as it made forgery more difficult. This was of utmost importance in Roman society as a seal stone often mounted in a ring was used only by its owner to validate serious legal documents.
The materials used for Roman intaglios differed little from the earlier Hellenistic period, with a great variety of coloured translucent stones coming from the East and Egypt including garnets, carnelian and amethyst. These gemstones were cut by using abrasive powder from harder materials. Emery has been mined for this purpose on the Greek island of Naxos for well over two thousand years until recent times. It largely consists of the mineral corundum, mixed with other minerals such as spinel and also rutile.
The highly specialised art of gem engraving was slowly lost during the later centuries of the Roman Empire, however there were major revivals of interest in engraved gems in Europe during the Byzantine era, the Middle Ages, the Renaissance, and again in the 18th and 19th centuries. A revival of the art of gem engraving began in 15th century Italy, where so many gems were being unearthed from Roman sites. These discoveries, which coincided with contemporary admiration for classical culture, inspired the emergence of a new school of gem engravers. The skills that had been lost for centuries were consequently studied and re-learned due to this renewed interest and the art was revived.
During the Neo-classical revival of the 18th century, connoisseurs avidly collected engraved gems of the ancient periods, along with copies by the most skilled engravers of the time. Through their collections, noted travellers and ‘dilettanti’ could confirm their elevated social status and display intellectual refinement and elegant taste. In this period ancient gems were regularly copied, and by 1800 there were flourishing studios working for royal or notable collectors in Italy, France, Germany and England. Laurentius Natter, a gem engraver of the 18th century, wrote ‘A treatise on the ancient method of engraving, compared with the modern’ in 1754. In this essay he describes the lathe and iron tools he used for engraving.
Natter explains that the size of the tools used gradually decrease from that of a large pea to the point of a fine needle, to be used in finer work. ‘One puts on the head of the tool some diamond powder moistened with philosopher-oil, which is the most thinnest and fixest than other oils. Then turning the great wheel with the foot, the stone (which is cemented with mastic to the end of a little stick) is applied to the tool to be engraved, the figure having been first drawn on it with the point of brass or diamond.’ This description is very similar to the tools and techniques that were used by the Romans almost 1000 years earlier.
The art of engraving gems was one of the prime arts of antiquity, with a tradition that continues through history. Due to the unique qualities of the gemstones together with the skill involved in cutting these materials, intaglios have remained greatly prized and collected.