CLASSICAL ENGRAVED GEMS AND FINGER RINGS
A gem (gemma in Latin) can be defined as a small piece of precious or semi-precious stone (the ancients did not make the same distinction as we do) that has been carved and polished, and which is usually set as an ornament in a piece of jewellery or in a variety of other settings (e.g. cult statues, walls, musical instruments, furniture, or even shoes in the case of the emperors Caligula and Elagabalus). Many of these gems are engraved with a device that is either cut in negative (an intaglio), or in positive (a cameo). Intaglios, usually mounted in the bezels of finger rings, are much commoner than cameos, which tend to be larger and set as pendants, or are even, in a few cases, unset objects in their own right. Glass was also used in imitation of more expensive stones. Intaglios, which form the largest part of the present catalogue, had a practical purpose: they served as official or personel seals. Besides this function, intaglios were used as ornaments or as amulets, which were believed to have curative and protective power.
A number of ancient authors wrote about gems but their texts are fragmentary or have not survived. The best accounts are by the fourth century B.C. philosopher Theophrastos (On Stones) and Pliny the Elder (Natural History), who wrote in the first century A.D. What we know today, however, is mainly deduced from the gems themselves.
The Functions of Engraved Gems
Beyond their aesthetic appeal as beautiful objects and ornaments, the primary function of engraved gems was to serve as seals. They were widely used to mark one's property, to record authority, and secure the privacy of objects and documents. A piece of clay or wax received the impression of an engraved stone or metal ring to signify ownership or authority. Such sealings could easily be broken when they secured a letter or an object, but their violation could not pass unnoticed. Ancient authors refer to the use of signet rings as seals: in one of Aristophanes' comedies, the women complain that the stores of meal, oil, and wine are guarded too well by their husbands' sealings. Another important use of seals was to secure valuable packages in the course of trade. The younger Pliny, as Trajan's official representative in Bithynia, wrote in c. A.D. 112 from Nikomedia that he was sending a gold nugget 'sealed with my own ring, with the device of a quadriga'. In modern terms, a seal on a letter would be akin to a signature or a sealed envelope, and when impressed on an object or a door it was equivalent to a padlock. In the ancient world most people could not write and the use of a personal seal was very handy as an identification mark. Nowadays, when the use of seals is uncommon, when signets are rarely cut and even more rarely used, it is not easy to appreciate the importance attached to them in antiquity. Clay sealings impressed by engraved gems set in rings have survived in great numbers throughout the ancient world. The represent the only remains of Greek and Roman archives once containing rolled and sealed papyrus documents. They usually owe their survival to the burning down of these archives, during which clay would be baked and become more resistant to the passage of time. A number of these archives contained sealings that span several centuries, such as those found at Doliche, a city of Kommagene at Düllük Tepe, probably dating from the late second century B.C. to the early third century A.D. some of these archives have each yielded more than 20,000 sealings. Clay sealings offer a vivid illustration of gems used as seals on official or private documents. Gems were precious objects, and were sometimes valued at astronomical prices. Pliny gives a number of examples of gems being exchanged for large sums of money. The nature and quality of the stone determined its value, whereas craftsmanship, it seems, did not significantly modify it. A story recorded by Herodotos and repeated by many authors, among them Pliny, is a very early testimony to the high esteem in which an engraved gem could be held. Since it involves the island of Samos, a few miles from the shores of Ionia, it is worth repeating here. The inhabitants of the independent island of Samos were under threat from the expanding Persian Empire, which had recently engulfed the kingdom of Lydia. A wealthy citizen of the island, Polykrates, seized power and made himself tyrant. To check the Persian advance, he allied his maritime forces to those of Amasis, Pharaoh of Egypt, who had similar concerns about the conquering Persians. Polykrates proved to be a good ruler and his strategy was effective at stopping the Persians' westward expansion. On being informed of the success of his ally, the superstitious Pharaoh Amasis wrote to Polykrates saying that the gods might be jealous of his success and that he should propitiate them by choosing from his treasures whatever he held most valuable and then disposing of it so that it would never again be seen by men. Polykrates considered carefully which of the treasures that he had in store would grieve him most to lose. After much thought he decided that it was a gold ring with the signet engraved on a fine smaragdos (most probably an emerald, or perhaps a green variety of chalcedony) by Theodoros, a fellow Samian celebrated for his gem-cutting skills. So he decided that throwing his ring into the sea would ensure that it would never be retrieved. This done he returned home and gave vent to his sorrow. But a few days later a local fisherman caught a very large fish which he thought fit for a king. He presented it to Polykrates who was pleased to accept it and in return invited him to partake of the fish at dinner. The cook cut the fish open and found the signet of his master in its belly. The precious ring was restored to Polykrates, but the Pharaoh Amasis, on being informed of these events, felt his ally could not be protected from his own fate and broke off the alliance. The prophecy was in due course realised when Polykrates was murdered by a Persian. Of course not all gems were as valuable as Polykrates', and in later periods many were produced in quantity for a popular market. In the Roman period, gems became more and more affordable, but their quality was proportionate to their price. During the Republic a gem set in a ring was mainly used for sealing. The common material for rings was iron, and to wear a gold ring was a mark of distinction. In the Roman Empire, however, the privilege was extended to people of lower rank and the number of rings worn by an individual increased. In the course of the first and second centuries A.D., gems and jewellery in general became increasingly common and no longer the preserve of a wealthy élite. Finds made in legionary camps throughout the Roman Empire suggest that many soldiers owned finger rings set with gems. These precious objects are very often found in the drains of public bath installations, where they had been accidentally lost. Since some sort of natural adhesive, such as resin or bitumen, was used to secure Roman ring-gems, in the hot and damp atmosphere of the baths they simply came unstuck. Although Romans must have been aware of the danger of losing their ring-gems, they continued to wear them, probably because of the belief that they were more vulnerable to harmful supernatural influences when naked and that their gems would protect them. There is ample evidence that gems were also connected with superstitious uses. Some were believed to have curative and protective powers. Pliny gives a long account of the magical properties of stones. He is generally critical of the superstitious claims made by the Persian magicians, the magi. A certain kind of agate, for instance, was said to be beneficial against bites of spiders and scorpions. Haematite was said to be good for the eyes and liver, caused petitions addressed to kings to succeed, was useful in lawsuits, and mixed with juice of pomegranate would cure those who vomited blood. The healing properties of gems were indeed very much in demand. A haematite gem in St Petersburg has an inscription which makes its function clear: stomachou (of the stomach). In the Roman period we find a marked incraese in teh number of gems used as talismans. In Egypt a particular kind of gem was engraved with syncretistic deities and magical inscriptions. Since these were not to be used as seals, the cutting is mostly in positive on the gem. Love spells were also cast by means of engraved gems, either to attract the favours of a reluctant lover, or take revenge on a cheating partner.
Materials
Most gems of the Greco-Roman period were made of hard stones of which quartz (silicon dioxide, SiO2; hardness of 7 on the Mohs scale) is by far the commonest type. There exists a wide range of quartzes of varying colours and appearance to which different names are applied. Colour could be invested with a quasi-magical function: red was the colour of blood and flesh, and green that of vegetation; amthyst was the colour of wine and as its name implies was a prophylactic against drunkenness.
The list given below is not intended to be comprehensive and only includes the minerals most frequently found. The task of identifying these gems is not a difficult one, since only about a dozen minerals were in common use. The more exotic stones represent just a fraction of ancient engraved gems. However, it is not always possible to match the ancient Greek and Latin terminology with known gemstones. It is a remarkable fact that Pliny gives some three hundred names to describe stones known and used in his time.
Chalcedonies or microcrystalline quartzes
Cornelian is a translucent red form of chalcedony, shading from dark red to golden yellow. The name derives from the Latin cornum, the red berry of the cornel-tree. The alternative name carnelian is generally considered incorrect, but the false etymology from carnis, 'flesh', has popularised its spelling. The whitish appearance of some ancient specimens is due to exposure to great heat.
Sard is a translucent brown variety of chalcedony, shading from light yellowish brown to opaque dark brown. Dark inclusions can sometimes be observed. Sard is often difficult to distinguish from cornelian. The cornelian and sard are the most widely used stones in Greek and Roman glyptic art. The name is derived from Sardis in Lydia, the place where it was chiefly found.
Sardonyx is used to describe chalcedony with straight bands of alternating brown or blue bands. It was the preferred stone for engraving cameos. The carver would take advantage of the colours in the layers to show, for instance, cream-coloured figures on a dark background, or to depict details of a drapery or a wreath. The term nicolo is used to describe a Roman banded intaglio with a blue or brown top layer and a dark brown bottom layer. Onyx, which derives from the Greek word for fingernail, a reference to the colour of the pale bands, is the name usually given to a black and white two-layered banded chalcedony.
Jasper is an opaque form of chalcedony and the most popular colours were red, orange and yellow. There is a green variety sprinkled with red spots popularly called bloodstone or heliotrope. Yellow and especially red jaspers became very fashionable for Roman gems in the second and third centuries A.D. Mottled jasper with small patches of white, brown, yellow and black was also occasionally used in the same period.
Chalcedony is a microcrystalline form of quartz and its different colours are due to the impurities that it has absorbed. The name is also generic, but is convetionally applied to colourless, grey and blue varieties. It derives from the name of the city Chalcedon (modern Kadıköy in Turkey).
Plasma is a green variety of chalcedony and often contains dark inclusions. The green colour is generally due to the presence of chrome. It is not a very accurate term, as it is applied to several different green stones, including aventurine, prase and chrysoprase.
Macrocrystalline quartzes
Rock crystal is transparent and colourless. It was more popular in the Greek period than in the Roman, when it appears only in the first century B.C.. Ancients believed that rock crystal was a form of petrified ice, the result of water being frozen at a very low temperature, the word 'crystal' being derived from the Greek word for ice. In Asia Minor, Pliny mentions that a poor variety occurred around Alabanda and Orthosia in Caria.
Amethyst is transparent and ranges in hue from dark purple to pale mouve. The colour is usually not distributed evenly in the stone, some parts being lighter, others darker. The name derives from the Greek word meaning 'not drunken', which originated from the belief that the wearing of the stone gave immunity against the after-effects of indulgence.
Other minerals
Lapis lazuli is deep blue and sometimes contains brassy specks of pyrite. It was highly prized since its only quarries were in Afghanistan, although Persia was also a possible source. In Roman times lapis lazuli was seldom used as a gemstone and most examples date to the second and third centuries A.D.
Garnet is a crystallised silicate. It is transparent and ranges in colour from dark red to orange, and sometimes purple, variants to which different names were applied in antiquity. It was not used until the Hellenistic period, when it became particularly fashionable. Its hardness was superior to that of quartz and it was thus more difficult to carve. In Asia Minor, Pliny mentions that it was extracted around the cities of Alabanda and Orthosia in Caria; the modern name almandine is a corrupt form of alabandina. A fiery red variety called lychnis is said by Pliny to have been found around Orthosia and throughout Caria. Garnets were very often carved with a curved surface and, to lighten the colour, the underside was holowed out.
Haematite is an iron oxide of dark metallic grey appearance. According to Theophrastos it was given that name because it looked like congealed blood, the word 'haematite' being derived from the Greek word for blood. Another explanation for the name is the red colour that haematite takes when it is powdered. It was infrequently used in the Greek period and most examples date from the Roman imperial period, when it was often made into magical intaglios.
In addition, glass was used throughout antiquity as a substitute for expensive gemstones. Some glass gems were directly engraved as in the same way as stone gems, other were cast from terracotta moulds made from the actual engraved stone gems, both intaglios and cameos. When the result was not entirely satisfactory, the glass impression was retouched to give it a sharper edge. Glass gems could also consist of several layers of varying colours, to reproduce sardonyx, nicolo, or banded agate. The glass could be opaque or translucent, with air bubbles often being visible on the latter variety. According to Pliny and other ancient authors, glass gems were often sold as stones by fraudulent dealers. One story tells us that the wife of Gallus, in the mid-first century B.C., bought a necklace of expencive beads only to find out that they were cheap glass. The dishonest seller was caught and duly hauled off to the arena where after a fearful wait he was confronted by a capon, not a lion, to the amazement of spectators; this was said to be a punishment that fitted the crime. It is clear, however, that most glass gems were sold as such, being more affordable and available in a whole range of fancy colours. Demand for them increased sharply from the first century B.C. onwards.
Methods of Engraving
The choice of cutting tools and techniques was determined by the nature of the object to be engraved. Only soft stones and metals could be worked free-hand with cutting tools. In the Greco-Roman period hard stones were mostly used, which required the wheel technique. Pliny and Theophrastos give brief accounts of the methods used for producing intaglios and cameos. Our knowledge of the tecniques used can also be deduced from the stones themselves and from modern methods.
Manageable pieces had first to be chipped from a block of raw stone. These were then shaped into blanks by grinding them against a fine abrasive wheel which was worked with a treadle like a lathe. Once the gem had been ground to the desired shape, it was polished with emery dust and then, to give it a glossy lustre, with finely powdered haematite (iron oxide). The polished blank was then engraved with the aid of drills made of copper and dipped in a mixture of oil and an abrasive. These drills were mainly of the bow-drill type, either hand-held or fixed. A string was wound around the shaft of the drill and the rigid bow was drawn back and forth. A representation of such a bow-drill fixed on a horizontal lathe has survived on the gravestone of the eighteen-year-old daktulokoiloglyphos, 'the cutter of intaglios', Doros of Sardis, which dates from the second century A. D. and was found at Philadelphia in Lydia. No ancient drill has survived, but useful information can be gained from the study of traces left in the intaglios themselves.
These drills were made of iron or copper-alloy and their grinding power was greatly enhanced by the use of an abrasive such as emery (an impure form of corundum with a hardness of 9), sources of which existed in Naxos in the Cyclades, southwest Turkey, and India.
The gem engraver used a combination of drills of various sizes, the cutting edge of which was in the shape of either a tiny disk or a ball.
There appears to be no decisive evidence to prove that gem engravers used magnifying lenses in antiquity. But it has been suggested that the craft was handed down from father to son in families that suffered from myopia and therefore had no problem in focusing close-up. Gem-cutters, like other artisans in the Hellenistic and Roman periods, would belong to guilds and the profession was usually passed from one generation to the next. Regional schools and styles did exist, but they are imperfectly known for lack of enough provenanced material.
A document from Egypt, the so-called Stockholm papyrus, indicates that the colour of gems was artificially modified, either to enhance a tonality or to change it altogether. These manipulations were evidently aimed at increasing the value of an average gem and varied with the fashion of the moment. Pliny describes the use of honey to colour agates. This method is still used today: a dull and grey-looking onyx is placed in boiling honey or sugared water, so that the sugar penetrates the stone and when heated is carbonised rendering the stone black. Stones could even be created artificially; Pliny tells us that sardonyx could be manufactured so convincingly by sticking three gems together that the artifice could not be detected.
The Choice of Designs on Engraved Gems
The designs engraved on gems reflect the fashion of their day. The principal motifs were pictorial and in the Roman period included reproductions of statues of deities, heroes, portraits, animals, mythological scenes and creatures, objects, symbols, and scenes from daily life. Deities were by far the most common, those worshipped by soldiers and merchants (Athena, Nike, Ares, and Hermes) being particularly popular. Portraits were also popular, both official and private. Many such portrait-gems have survived of Hellenistic kings and Roman emperors. Some were distributed to favoured subjects and evidently had a propaganda value. In the Roman Republic, it was considered an honour to have a portrait of a distinguished ancestor on a seal. Family ancestry also played a role in the choice of the design of a signet-ring. This can be compared to our modern rings bearing family crests or coats of arms. Julius Caesar, for instance, had on his seal an armed Venus (Venus Victrix), since he claimed descent from that goddess through Aeneas. On a different note, we are told by Clement of Alexandria that some people even had figures of their naked mistresses on their seals.
Animals were also very popular and often had a symbolic meaning. The ram's head, for instance, was an emblem of good fortune. Eagles were particularly popular with legionary soldiers. Sometimes the design of a gem cannot be readily interpreted when it involves the combination of characters or objects that have lost their meaning. Combinations of several figures, masks, parts of animals, heads of satyrs, etc., usually known as grylloi (gryllos, a misnomer, means caricature), were in great favour from the first century B. C. onwards. These were not merely fanciful but had a recognised superstitious significance. They were worn as amulets to avert the evil eye or ensure fertility and prosperity for the owner. Early Christian and Byzantine gems emphasised religious motifs, and monograms of individual names are also common.
Some stones, on account of their colour and properties, were specifically used for certain motifs. From the second century A. D. onwards, lions were very often engraved on yellow jasper, presumably to render the natural colour of the lion's mane. Bloodstone and haematite were popular stones for magical gems in Egypt. Intaglios cut on bloodstone frequently portray the sun god Helios, which is partially explained by the Greek name of the gem, heliotrope. Many amethyst or mauve glass gems with a mask of Dionysos engraved on them have survived and provide an attractive combination of the prophylactic property of the stone (protection from drunkenness) with the image of the inebriating god of wine.
Dating Engraved Gems
Gems cannot be dated as accurately as other artefacts such as coins, ceramic shards or sculpture fragments. Style, technique and subject, as well as the variety and shape of gems, are useful dating criteria, but they remain relative indicators. There has been recently an increase in the number of studies focusing on the techniques of engraving, and chronological systems have been devised on the basis of these observations. Such efforts are constantly checked by finds of gems from dateable contexts. Recently, for instance, the dating of the 'Incoherent grooves style' has been down-dated in view of new finds. A good example of a securely dated context is the house of Pinarius Cerialis in Pompeii, in which a jewellery box containing a number of plain and engraved gems, among them 24 intaglios and six cameos, was found. This hoard is of value in providing an undisputed chronological pointer, for all must have been made before the destruction of the city in 79 A. D.Tomb finds are also very useful evidence for advancing our knowledge, as they are sometimes associated with other dateable objects such as coins. One difficulty, however, is the long survival rate of gems, which could be passed as heirlooms from one generation to another. Examples of old gems set in later rings are not uncommon.
Shapes and materials used for rings have also evolved with time, and these variations can also help in dating the gems set in them. When specialists date a gem, they usually do so within a century or two, and at best within half a century. Unless there is conclusive dating evidence, such as the portrait of an emperor whose regnal years are known, any attempt at greater accuracy would only be rash in the present circumstances. Future finds coupled with more thorough studies will no doubt refine what is today a choronological arrangement that is only partially satisfactory.
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