Antiqued Marcasite Hoop Sterling Silver Earrings

In marcasite jewelry, pyrite used as a gemstone is termed "marcasite". That is, marcasite jewelry is made from pyrite not from marcasite. In the late medieval and early modern eras, the word "marcasite" meant both pyrite and marcasite (and iron sulfides in general). The narrower, modern scientific definition for marcasite as orthorhombic iron sulfide dates from 1845. The jewelry sense for the word pre-dates this 1845 scientific redefinition.