Pyrite

Real mineral · common · FeS₂

Iron sulfide that crystallises in perfect cubic forms. Its metallic yellow surface mimics gold closely enough to deceive prospectors for centuries. Oxidises to iron oxide and sulfuric acid when exposed to air and water.

Identity

Formula

FeS₂

Chemical class

sulfide

Also known as

Fool's gold, Iron pyrite

Crystallography

Crystal system

cubic

Habits

cubic, octahedral, dodecahedral, massive

Fracture

conchoidal

Physical properties

Mohs hardness

6.5

Density

5.02 g/cm³

Luster

metallic

Colors

metallic yellow, brass-yellow, pale brass-yellow

Streak

black

Transparency

opaque

Geology

Origins

hydrothermal, sedimentary, metamorphic, igneous

Host rocks

shale, coal, granite

Associated minerals

Quartz, Calcite, Gold, Chalcopyrite

Geography

worldwide

Classification

Rarity

common

Gem quality

No

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