Pyrite (Iron Sulfide)

From Ohio History Central

The name of this mineral comes from an ancient Greek word for fire. Because of the bright yellow color of many examples of pyrite it sometimes is called "fool’s gold." Pyrite is very common in the earth’s crust. It has been used as an ore for sulfur, and sometimes as a source of iron. The more easily mined hematite, however, is a preferred source of iron. During the Second World War when North American sources of native sulfur were being used up, pyrite was mined for its sulfur content. Pieces of pyrite can be cut and polished and are used as ornamental stones. These sometimes mistakenly are called marcasite, which is a different mineral.

Facts

Chemical Composition:Iron Sulfide (FeS2)
Mineral Class:Sulfides
Crystallization:Isometric
Crystal Habit:Commonly well crystallized; may be granular or finely crystalline and massive; sometimes found as a replacement mineral of fossils.
Specific Gravity:4.9 - 5.2
Hardness:6 - 6 1/2
Color:Pale brass-yellow
Transparency:opaque
Luster:Metallic
Streak:Greenish black
Occurence:<img width="195" height="172" src="images/naturalHistory/minerals/pyritemap.gif" alt="" />

Notes

Pyrite is found in a great many localities, with some of the more noteworthy being in North America and Europe. It has been reported from 58 counties in Ohio. Pyrite occurs in brassy crystals or sometimes as nodules in Devonian and Pennsylvanian shales. In western Ohio small crystals and finely granular coatings of pyrite occur in cavities and fractures of dolostone. In eastern and northwestern parts of the state nodules occur commonly in shale, less commonly in dolostone. Nodules, lenses and bands of pyrite are common in many of the coal beds of eastern Ohio. And also in the eastern part of the state small crystals and finely granular aggregates are common in ironstone nodules.

Resources

  • Carlson, Ernest H., ed. Minerals of Ohio; Ohio Division of Geological Survey, Columbus, OH; Bulletin 69; 1991.
  • Pough, Frederick H. A Field Guide to Rocks and Minerals; Houghton Mifflin, Boston, MA; 1976.
  • Sorrell, Charles A. Rocks and Minerals; Golden Press, New York, NY; 1973.

See Also