Swarovski tells us that: "Marcasite is a genuine, natural gemstone. Marcasite is derived from a natural mineral called 'pyrite'. Pyrite is found in many parts of the world, but only a small fraction of it is suitable for the cutting processes required to create marcasite jewelry. Marcasite is both an elegant and fashionable gemstone. Marcasite has been used for personal adornments as far back as in ancient times.
"Many years ago, in ancient times, people believed that marcasite had the power to discharge negative energy, improve a person’s communication abilities, and protect those who performed dangerous jobs.
"During the reign of Louis 14th of France, only the King was allowed to wear genuine diamonds. Marcasite became very popular in the region as a diamond imitation, and was worn by high society and also by women at court. During Queen Victoria’s reign in the 19th century, marcasite jewelry was cherished in the UK both for its elegance, and for its ability to be combined with pearls. It quickly gained in popularity and soon reached a wide audience."