History ДЄntelopes attacked by birds: cylinder seal in hematite and its impression. Many of these can be shown to have been used since antiquity вЂ“ since the 7th millennium BC in the case of heating. The colour of several gemstones can be enhanced by a number of artificial methods, using heat, sugar and dyes. In intaglio gems at least, the recessed cut surface is usually very well preserved, and microscopic examination is revealing of the technique used. Byzantine cutters used a flat-edged wheel on a drill for intaglio work, while Carolingian ones used round-tipped drills it is unclear where they learnt this technique from. A medieval guide to gem-carving techniques survives from Theophilus Presbyter. There is no evidence that magnifying lenses were used by gem cutters in antiquity. Some early types of seal were cut by hand, rather than a drill, which does not allow fine detail. Emery has been mined for abrasive powder on Naxos since antiquity. Gems were mostly cut by using abrasive powder from harder stones in conjunction with a hand-drill, probably often set in a lathe. A finely carved seal was practical, as it made forgery more difficult вЂ“ the distinctive personal signature did not really exist in antiquity. Though they were keenly collected in antiquity, most carved gems originally functioned as seals, often mounted in a ring intaglio designs register most clearly when viewed by the recipient of a letter as an impression in hardened wax. Glyptics or glyptic art covers the field of small carved stones, including cylinder seals and inscriptions, especially in an archaeological context. Vessels like the Cup of the Ptolemies and heads or figures carved in the round are also known as hardstone carvings. References to antique gems and intaglios in a jewellery context will almost always mean carved gems when referring to monumental sculpture, counter-relief, meaning the same as intaglio, is more likely to be used.

The activity is also called gem carving and the artists gem-cutters.

This article uses cameo in its strict sense, to denote a carving exploiting layers of differently coloured stone.

Strictly speaking, engraving means carving in intaglio (with the design cut into the flat background of the stone), but relief carvings (with the design projecting out of the background as in nearly all cameos) are also covered by the term. The engraving of gemstones was a major luxury art form in the Ancient world, and an important one in some later periods. Perhaps 14th century.ДЄn engraved gem, frequently referred to as an intaglio, is a small and usually semi-precious gemstone that has been carved, in the Western tradition normally with images or inscriptions only on one face.

Intaglio cameos