Marcasite Value, Price, and Jewelry Information


marcasite - Canada
“Marcasite,” Flambrough Quarry, Dundas, Hamilton, Wentworth County, Ontario, Canada. © Rob Lavinsky, www.iRocks.com. Used with permission.

Marcasite has a long history of use as a decorative and jewelry material. However, this brassy colored, metallic stone is quite brittle and seldom seen in modern jewelry.

Marcasite Value

The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.

Marcasite Information

DataValue
NameMarcasite
Crystallography Orthorhombic. Crystals abundant, tabular, pyramidal, often with curved faces; also massive; granular; radial; globular; cockscomb-shaped aggregates.
Colors Pale brassy yellow, green-yellow, brownish, to whitish.
Luster Metallic
Fracture Fracture uneven. Brittle.
Hardness 6-6.5.
Specific Gravity 4.85-4.92.
Cleavage Distinct 1 direction.
Transparency Opaque
Phenomena May be iridescent.
FormulaFeS2
EtymologyFrom the Arabic marqashītā for pyrite.
OccurrenceMarcasite forms at low temperatures, especially in sedimentary environments such as clays, shale, coal beds, and in low temperature veins.
marcasite - Portugal
“Marcasite,” Panasqueira, Portugal. © Rob Lavinsky, www.iRocks.com. Used with permission.

Comments

Despite marcasite’s relatively low hardness and distinct cleavage, many cultures have worked this material into objects of beauty. The Ancient Greeks made jewelry from marcasite. The Incas of South America polished large slabs of it as decorative objects. Gem cutters in the Victorian Era faceted this material into stones with flat backs. This popular style was known as the flattened-rose cut. Jewelry makers set them in white metal settings, such as rhodium-plated silver.

Nevertheless, much of the material found in these antique jewelry pieces is actually pyrite, a dimorph or polymorph of marcasite. These minerals share the same chemistry but have different crystal habits. (Pyrites have greater stability than marcasites for jewelry wear). For a time, they even shared the same name. Miners called common crystallized pyrite gemstones marcasites until the 19th century.

marcasite jewelry
“Marcasite Brooch Made from Silver and Pyrite” by jo-marshall. Licensed under CC By 2.0.

Identifying Characteristics

Marcasites leave a greenish black streak. However, never conduct a destructive streak test on a finished stone.

You may find steel imitations of this material. However, steel may be magnetic while marcasite is not.

Sources

This mineral is abundant and found throughout the world. Notable sources of gem material include:

  • United States: Illinois; Kansas; Missouri; Oklahoma; Wisconsin.
  • United Kingdom, England: in chalk deposits along the coast and at Folkestone.
  • Austria; Bolivia; Czech Republic; France; Germany; Myanmar; Slovakia.
marcasite - France
“Marcasite,” Cap Blanc Nez, France, by GorissenM. Licensed under CC By-SA 2.0.

Stone Sizes

Massive material exists. Gem cutters can fashion cabochons of any desired size.

Care

Since marcasite can react to moisture and release sulfuric acid, store specimens in low humidity, below 60%, and separate from other pieces. Avoid inhaling dust when cutting this material and wash your hands after handling.

Marcasites are quite brittle. A sharp blow can easily crack a stone and loosen it in its setting. Because of its fragility and reaction to moisture, jewelry use is not recommended.

marcasite - England
“Marcasite,” Folkestone, England. © Rob Lavinsky, www.iRocks.com. Used with permission.