Pearls were in particular favour as ornaments for the ears. Introduced into Rome about the time of Sulla, pearls were imported in large quantities during the Roman domination of Egypt. In Vespasian's time Pliny, referring to earrings, says: "They seek for pearls at the bottom of the Red Sea, and search the bowels of the earth for emeralds to decorate their ears." Perfect spherical pearls of delicate whiteness were termed _uniones_ (i.e. unique), since no two were found exactly alike. Pear-shaped pearls, called _elenchi_, were prized as suitable for terminating the pendant, and were sometimes placed two or three together for this purpose. Thus worn, they were entitled _crotalia_ (rattles), from the sound produced as they clashed together. "Two pearls beside each other," Seneca complains, "with a third on the top now go to a single pendant. The extravagant fools probably think their husbands are not sufficiently plagued without their having two or three heritages hanging down from their ears." Earrings with single pendants were called _stalagmia_. It is especially to be noticed that the shapes of all ancient jewellery and ornaments, particularly those of the Romans, were in a great measure decided by a belief in their magical efficiency. The wearing of amulets was most frequent among the Romans of all classes. They were generally enclosed in a _bulla_, and suspended from the neck. A remarkable specimen of a _bulla_, found at Herculaneum, and presented by the Court of Naples to the Empress Josephine, is now in the Ashmolean Museum at Oxford. The lentoid-shaped _bulla_ was worn almost entirely by children, but other pendants, shaped like pendent vases, or in the form of a square or cylindrical box, were a not unusual ornament of the necklace of Roman ladies. They probably always possessed a symbolical meaning. The simple neck-chain, whether supplied with the appendage or not, was called a _monile_; the luxury of latter times doubled or trebled the rows of chains. These were often of finely plaited gold or else of links. Other necklaces were composed of mounted precious stones, the fashion for which appears to date from the Oriental conquests of Pompey in the first century B.C. Vast quantities of precious stones were brought into Rome at that date; for the treasury of Mithridates, captured at Talaura, contained, besides many other precious objects, "jewels for the breast and neck all set with gems." The Romans also wore necklaces (_monilia baccata_) composed of beads of various materials, both precious stones and glass, of many colours and various shapes. Amber was largely employed for the purpose, and held in high estimation by Roman ladies, who regarded it not only as an ornament, but as a talisman for protection against danger, especially witchcraft. Amber in which small insects were enclosed was particularly prized: "the price," says Pliny, "of a small figure in it, however diminutive, exceeds that of a living healthy slave."