mineral

Pyrite (on Quartz/Sulfide matrix)

Iron Sulfide (FeS2)

Hardness: 6–6.5 Mohs scale; Color: Pale brass-yellow to brassy gold; Luster: Metallic; Crystal Structure: Isometric (typically cubes, pyritohedrons); Cleavage: Indistinct; Specific Gravity: 4.9–5.2.

Hardness: 6–6
Color: Pale brass-yellow to brassy gold
Luster: Metallic

Identified March 27, 2026More mineral →

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Physical properties

Formation & geological history

Formed in both igneous and metamorphic environments, often as a result of hydrothermal activity or precipitation from sulfur-rich fluids. It occurs globally in rocks of almost all geological ages.

Uses & applications

Major historical source of sulfur and sulfuric acid. Today, it is primarily used as a collector specimen, in jewelry (often sold as 'marcasite'), and for the manufacture of small components in lithium batteries.

Geological facts

Commonly known as 'Fool\'s Gold' because its color and weight are similar to real gold. It is distinguished from gold by its brittleness and hardness (gold is soft and can be scratched with a penny).

Field identification & locations

Identify in the field by its metallic luster, greenish-black streak, and cubic crystal habit. It is found globally, with notable deposits in Spain, Peru, Italy, and the USA. Collectors should look for sharp crystal edges and avoid specimens showing 'pyrite disease' (oxidization).

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