The name Marcasite is derived from the Arabic word for pyrite however Marcasite has the same chemistry as pyrite but a different structure and, therefore, different symmetry and crystal shapes. Marcasite is a common and an attractive mineral. Marcasite is often mistakenly confused with pyrite, but marcasite is lighter and more brittle. Adding to the confusion between marcasite and pyrite is the use of the word marcasite as a jewelry trade name. The term is applied to small polished and faceted stones that are inlayed in sterling silver. Pyrite used as a gem is improperly termed "marcasite". Marcasite is never used as a gem. "Marcasite" Jewelry is therefore a combination of sterling silver and white iron pyrite.