Marcasite jewellery is jewellery made from pyrite (fool's gold), not, as the name suggests, from marcasite. Pyrite is similar to marcasite, but more stable and less brittle. Marcasite jewellery has been made since the time of the Ancient Greeks. It was particularly popular in the eighteenth century, the Victorian era and with Art Nouveau jewellery designers. It is frequently made by setting small pieces of pyrite into silver. Cheaper costume jewelry is made by glueing pieces of pyrite rather than setting. A similar-looking type of jewellery can be made from small pieces of cut steel.
The gleam of marcasite made it attractive and when diamonds were banned from public display in Switzerland in the 18th century marcasite, along with cut steel, was turned to as a replacement.