摘要：Jet (German Gagat/Pechkohle, French jaïet, jais, Croatian gagat, Spanish azabache, Italian giaietto) is a type of bituminous coal of a velvet-black or brown colour, with a waxy or greasy shine. In fact, it is fossilised wood from the Araucariaceae family, from the Jurassic period, more than 180 million years ago. Because of its organic origin it is not considered a stone, but due to its features it is listed among precious materials. The word jet (Croatian: gagat) originates from Greek γαγάτης, Latin lapis gagates, after the town and river of Lycia, in the region in Asia Minor, where it was first discovered. Jet is very easily polished and can be used as a gemstone. It is highly inflammable, and when set on fire it has a very unpleasant smell. It becomes magnetised if rubbed with wool, just like amber. Although jet is not hard, it is hard enough to be worked, engraved and polished, but it requires great skill. It can also be given a sheen with oak oil. Jet is found in coal mines in the shape of round stones of different dimensions. The most famous deposits of jet in the world are in England (North Yorkshire, in the surroundings of the town of Whitby), in Germany (in the Rhine and Mosel river basins), in France (Languedoc), Spain (Asturia, the province of Oviedo), the United States of America (Colorado, Utah), the Czech Republic, Slovakia, Poland, and Portugal. It is found in amber mines in Germany, where it functions as a “coat” for the amber which it greatly resembles, and this is why it is also called black amber. Jet has been used for making jewellery ever since the Palaeolithic and Neolithic ages, but only in the Bronze Age was its full potential revealed, when the production of finely worked pieces of jewellery, bracelets, pearls, rings and similar items began. The use of jet as a gemstone also continued into the Iron Age and the Roman period. In Antiquity, it was also used for making jewellery: necklaces (threaded beads and grains of various sizes), pendants and medallions, bracelets, rings, hairpins, as well as whorls and spindles, knife handles, gaming chips, and various kinds of figurines - amulets. The Romans particularly valued jet for its alleged medicinal qualities. While working on cataloguing the materials in the depots of the Archaeological Museum in Zadar, I separated a large group of fragments that mostly have not been entered into the inventory or registered, as well as several complete bracelets and other artefacts made of jet and dark (black) glass. I managed to separate a group of fragments and artefacts made of jet and pseudo-jet from the holdings of the Museum - several hundreds of fragments - which are now being processed. I selected the most beautiful samples from this group, and have catalogued these 22 items in this paper. Among these pieces of jewellery, the most numerous are bracelets (armilla). A particularly interesting bracelet is the one from Zadar, on both sides of which two dog heads in relief are set toward the bracelet’s rectangular central part. I have not found any similar example in the literature available to me. Some people believe that jewellery made of jet was worn by the priests and priestesses of the Great Mother (Magna Mater) or Cybele, that is, the men and women introduced into the secrets of the Metroac religion. Why a dog, then? A dog is not a typical iconographic attribute of the Great Mother, but it appears in her iconography in Gaul, where the cult of the Great Mother was contaminated by Gallic Mothers (Matres), goddesses of fertility, waters, and health. I also processed three necklaces (monilia) made of threaded beads and several beads of various sizes. There are also several pendants among the finds. A pendant in the shape of an eagle’s head can be connected with an eagle as an attribute of the supreme Roman god - Jupiter, “the bird king,” the symbol of power, strength, and victory. It is also the symbol of the Roman state. Two of the pendants contain impressed male and female busts, and one of them only a female bust. Pendants with male and female busts are also called engagement medallions. According to their typology, two catalogued rings (anuli) do not differ from the metal rings. It is impossible to answer the question of the origin of these pieces of jewellery. There are indications that a jet workshop existed in Trier, Germany, but there are also investigators who are inclined toward the thesis that the jet found in Germany had been imported from England. It is impossible to answer this question, for these jet finds are insufficiently investigated. Indeed, it would primarily be necessary to determine the geological source of every single item made of jet. In Europe, artefacts made of jet and cheaper pseudo-jet are often found among the funerary gifts in the necropolises of the 3rd and 4th century, in Germany (Trier, Mainz, Bonn, Cologne, Gellep, Bregenz), then in Italy, Hungary, Bulgaria, northern France and Belgium. Pseudo-jet is a somewhat less appreciated version of jet, and is therefore cheaper, for its structure is worse and its colour is brown and grey. The richest finds are from England, where the best quality jet originates from North Yorkshire, from the surroundings of the town of Whitby.
