This attractive form of jewelry dates back to the time of the Ancient Greeks. According to the internet, marcasite first came into fashion as a gemstone under the reign of Louis XIV of France, when it was crafted into floral sprays and rosettes for brooches and buckles. It again became very fashionable and popular in Victorian times when Queen Victoria is said to have favored marcasite in her jewelry. Other eras of popularity include the Roaring Twenties after World War I and again embraced during the Art Noveau and then Art Deco periods. Today it's being used to create a vintage or an old world look in a modern piece.