Pyrite

Object/Artifact

-

Crater Rock Museum

Name/Title

Pyrite

Entry/Object ID

2004.1.11

Description

Assemblage Zone: pegmatitic dikes Chemical Composition: FeS2 Crystal System: Cubic or Isometric S Description: Common Name: Pyrite Chemistry: FeS2, Iron Sulfide Class: Sulfides Group: Pyrite Uses: A very minor ore of sulfur for sulfuric acid, used in jewelry under the trade name "marcasite" and as mineral specimens. Location: Found in the Huanzala Mine, Huallanca District, Dos de Mayo Province, Huanuco Department, Peru. PHYSICAL CHARACTERISTICS: Color is brassy yellow. Luster is metallic. Transparency: Crystals are opaque. Crystal System is isometric; bar 3 2/m Crystal Habits include the cube, octahedron and pyritohedron (a dodecahedron with pentagonal faces) and crystals with combinations of these forms. Good interpenetration twins called iron crosses are rare. Pyrite is commonly found in nodules. A flattened nodular variety called "Pyrite Suns" or "Pyrite Dollars" is popular in rock shops. Also massive or reniform and replaces other minerals and fossils forming pseudomorphs or copies. Cleavage is very indistinct. Fracture is conchoidal. Hardness is 6 - 6.5 Specific Gravity is approximately 5.1+ (heavier than average for metallic minerals) Streak is greenish black. Other Characteristics: Brittle, striations on cubic faces caused by crossing of pyritohedron with cube. (note - striations on cube faces also demonstrate pyrite's lower symmetry). Pyrite (unlike gold) is not malleable. Associated Minerals are quartz, calcite, gold, sphalerite, galena, fluorite and many other minerals. Pyrite is so common it may be quicker to name the unassociated minerals. Best Field Indicators are crystal habit, hardness, streak, luster and brittleness. Fracture: conchoidal Hardness: 6 Orthoclase Luster: Metallic Occurrence: Occurs in rocks, intramagnetic deposits, hydrothermal veins, as concretion in sediments, in metamorphic deposits. Rock Color: Light Rock Type: Igneous Specific Gravity: 5.1+ Streak: Greenish Black Texture: Crystaline Variety: Pyrite is the classic "Fool's Gold". There are other shiny brassy yellow minerals, but pyrite is by far the most common and the most often mistaken for gold. Pyrite is a polymorph of marcasite, which means that it has the same chemistry, FeS2, as marcasite; but a different structure and therefore different symmetry and crystal shapes. Pyrite is difficult to distinguish from marcasite when a lack of clear indicators exists

Collection

Suomynona Mineral Collection, Suomynona Collection

Acquisition

Accession

2004.1

Source or Donor

Suomynona Mineral Collection

Acquisition Method

Donation

Dimensions

Width

4-1/2 in

Depth

2-3/4 in

Length

5-1/2 in

Weight

5.1 oz

Dimension Notes

Dimension taken at widest points

Location

Location

Display Case

FS-16

Room

Frieda Smith Hall

Building

Crater Rock Museum

Category

Permanent

Moved By

Ian Cunningham

Date

February 7, 2024