Dating Engraved Gems

ANCIENT GEMS AND FINGER RINGS FROM ASIA MINOR

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.