Marcasite used in jewelry is really the mineral iron pyrite.  They both have the same chemical composition but a different crystal structure.  This results in pyrite being stable while marcasite can crumble.  It is an attractive and interesting mineral that is used in sterling silver jewelry.  Small polished and faceted stones are inlaid into the silver which adds an extra sparkle to the jewelry.  The stones have a metallic luster and are opaque.

Marcasite first came into fashion as a gemstone under the reign of Louis XIV of France, when it was set in silver and crafted into floral sprays and rosettes for brooches and buckles.  The use of marcasite in jewelry was very fashionable and popular in Victorian times and Queen Victoria is said to have favored marcasite in her jewelry.  Marcasite jewelry regained popularity in the Roaring Twenties after World War I and fit perfectly into the Art Deco style.  Today it gives jewelry a vintage look by adding an old world quality to modern jewelry.

the mineral pyrite