Niello is a black metallic alloy of sulfur, copper, silver, and usually lead, used as an inlay on engraved metal. It can be used for filling in designs cut from metal. The Egyptians are credited with originating niello decoration, which spread throughout Europe during the Middle Ages.
The goldsmiths of Florence in the middle of the 15th century ornamented their works by means of engraving the metal with a burin, after which they filled up the hollows produced by the burin with a black enamel made of silver, lead and sulfur. The resulting design, called a niello, was much of higher contrast and thus much more visible.
The technique is as follows: The artisan would carve a particular character or pattern into the silver, leaving the figure raised by carving out the "background". He would then use the niello inlay to fill in the "background". After being baked in an open fire, the alloy would harden. It would then be sanded smooth and buffed. Finally, a silver artisan would add minute details by hand. Filigree was often used for additional ornamentation. Nielloware is classified as only being black and silver colored. Other colored jewelry originating during this time uses a different technique and is not considered niello.
Although there is not much commercial value to nielloware jewellery, they are wonderful keepsakes and often hold sentimental value. They are easy to match and provide interesting conversation pieces.
Common nielloware pieces include: necklaces, bracelets, brooches, tie bands, rings, earrings, pendants, buttons, and snuffboxes.
During the 10th to 13th century A.D. Kievan Rus craftsmen possessed a higher degree of skill in jewelry making than craftsmen elsewhere in the world. Through the perfected use of techniques including hot working of iron, wax and stone molds, inlay with niello and cloisonné enamel, the works of Kievan Rus craftsmen had no equal in the world market during that time period. John Tsetses, a 12th century Byzantine writer praised the work of Kievan Rus craftsmen and likened their work to the creations of Daedalus, the highly skilled craftsman from Greek Mythology.
Niello was used on a variety of object including sword hilts, chalices, plates, horns, adornment for horses, and most prolifically, jewelry for women: necklaces, bracelets, rings, torques, pendants, buttons, belt buckles, headdresses, etc.
The Kievan Rus technique for niello application was first shaping silver or gold by repousse, embossing, and casting. They would high relief objects and fill the background with niello using a mixture of red copper, lead, silver, potash, borax, sulfur which was liquefied and poured into concaved surfaces before being baked in a furnace. The heat from the furnace would blacken the niello and allow other ornamentation to stand out more vividly.
Nielloed items were mass produced using molds that still survive today and were traded with Greeks, the Byzantine Empire, and other peoples that traded along the trade route from the Varangians to the Greeks.
During the Mongol invasion from 1237 to 1240 A.D. the whole of Kievan Rus was overrun and villages and workshops were burned and razed to the ground and most of the craftsmen and artisans were killed. Afterwards skill in niello and cloisonné enamel diminshed greatly.