mineral

Pyrite (Fools Gold)

Iron Sulfide (FeS2)

Hardness: 6-6.5 on Mohs scale; Color: Pale brass-yellow to golden; Luster: Metallic; Crystal system: Isometric/Cubic; Cleavage: Indistinct; Specific Gravity: 4.9-5.2; Streak: Greenish-black

Hardness: 6-6
Color: Pale brass-yellow to golden
Luster: Metallic

Identified May 28, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 6-6.5 on Mohs scale; Color: Pale brass-yellow to golden; Luster: Metallic; Crystal system: Isometric/Cubic; Cleavage: Indistinct; Specific Gravity: 4.9-5.2; Streak: Greenish-black

Formation & geological history

Forms in a variety of geological settings including hydrothermal veins, as an accessory mineral in igneous rocks, in contact metamorphic rocks, and in sedimentary rocks like coal and shale. Found in rocks of all ages from Precambrian to Holocene.

Uses & applications

Primarily used in the production of sulfur dioxide for the paper industry and sulfuric acid for chemical applications. Occasionally used in jewelry (labeled as ' marcasite') and as a popular specimen for collectors.

Geological facts

Pyrite is called 'Fools Gold' because its color and high specific gravity can easily deceive inexperienced prospectors. It is the most common sulfide mineral on Earth. To tell it apart from real gold, one can perform a streak test (pyrite is black/greenish, gold is yellow) or a hardness test (pyrite is much harder).

Field identification & locations

Identified by its brassy color, cubic crystal habit, and metallic luster. In the field, look for distinct cubic shapes or striated faces. Common in mining districts worldwide, such as Rio Tinto in Spain or various locations in the Rocky Mountains.