While most jewelry is sold under the name of marcasite, it is actually a pyrite stone. Marcasite is brittle and light and can be easily broken or crumble apart which is why it is not actually used in jewelry. Pyrite has a hardness of 6 to 6.5 on the Mohs scale, which is hard enough to use in jewelry settings. Marcasite is popular for its dark bronze metallic luster. It can be found at a very reasonable cost since it is mined and manufactured in several locations all over the world.
Marcasite was first used in jewelry in the early 1700s by the Swiss who used it as a replacement for diamonds. It also became popular in the Victoria Era from 1837 to 1901 and is associated with vintage, old-fashioned or estate jewelry. Other minerals that are associated with marcasite are quartz, pyrite, calcite, dolomite, fluorite and other sulfides.
Most of the time, marcasite is secured into jewelry settings by jeweler’s cement. It is too brittle and unstable to be secured by prongs. Most often, marcasite is set into sterling silver settings.
Marcasite jewelry can be cleaned with a soft, dry cloth to keep it looking shiny and bright. Marcasite jewelry should never be placed in an ultrasonic cleaner or used under a steamer. Harsh chemicals should never be applied to the marcasite stones.
The color of marcasite can be brassy yellow with a greenish tint. Marcasite may have a multi-colored tarnish which is a result of oxidation. The unique metallic color of the marcasite stone is typically complemented with a silver or white gold jewelry setting. The stones are often paired with onyx in jewelry as well. Because marcasite looks antique in nature, new jewelry styled in an antique or vintage way is a popular use for marcasite jewelry.
Marcasite used for jewelry is mined all over the world. In the United States, marcasite can be found primarily in Utah, Missouri, Pennsylvania and Illinois. Internationally, marcasite can be found in Peru, Germany, Spain, Russian, South Africa, Sweden and Italy.