A type of metal neck ring or armlet or, rarely, a girdle in the shape of a penannular hoop, the terminals being in the form of ornaments of many forms and styles. Such pieces are generally associated with Celtic jewelry, but an armlet (in the British Museum) of bent silver wire from Egypt, c. 1800 BC- 1500 BC, has suggested possible early Asiatic sources.
Examples are known from the La Tθne culture, c. 5th/1st centuries BC, found mainly in eastern France; these are solid cast bronze, almost undecorated except the hollow buffer or discoidal terminals. Some have decoration in the Waldalgesheim style, and some of the 2nd/1st centuries BC have terminals of a double-hour-glass style.
Among the examples found in Britain, at Ipswich, Suffolk, and Snettisham, Norfolk, from the British Later Bronze Age, 1st century BC, are some of gold alloy, made either as two circular bars twisted together or in rope-like style twisted strands, and having ring or loop terminals, sometimes ornamented in relief or with engraving.
Examples found in Ireland from the Bronze Age are made from twisted rods or twisted flat metal strips. The torc, long regarded as the principal ornament of Celtic jewelry, has been mentioned by some writers as worn by Celtic warriors, but those that have been found in graves in England are around the necks of women and girls. It has been suggested that, in view of the precise weight of some examples (either alone or with some accompanying article as a makeweight), they may never have been made to be worn but were used as currency jewelry.
From: An Illustrated Dictionary of Jewelry, autor: Harold Newman, publishers: Thames and Hudson