mineral

Pyrite (Iron Pyrite)

Iron Sulfide (FeS2)

Hardness: 6-6.5 Mohs. Color: Brass-yellow to pale gold. Luster: Metallic. Crystal structure: Cubic or isometric. Cleavage: Poor. Specific gravity: 4.9-5.2.

Hardness: 6-6
Color: Brass-yellow to pale gold
Luster: Metallic

Identified March 15, 2026More mineral →

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Physical properties

Hardness: 6-6.5 Mohs. Color: Brass-yellow to pale gold. Luster: Metallic. Crystal structure: Cubic or isometric. Cleavage: Poor. Specific gravity: 4.9-5.2.

Formation & geological history

Forms in diverse environments including igneous, metamorphic, and sedimentary rocks. It often precipitates from hydrothermal fluids or forms in stagnant water environments where sulfur is present. It is found in rocks of all geological ages.

Uses & applications

Historically used as a source of sulfur and in firearms (wheellock). Currently used in industry for the production of sulfuric acid, in small amounts in electronics (lithium batteries), and extensively in jewelry (as marcasite) and mineral collecting.

Geological facts

Commonly known as 'Fool's Gold' due to its metallic luster and yellow hue, which often led novice prospectors to mistake it for gold. Unlike gold, pyrite is brittle and leaves a black or greenish streak on a porcelain plate.

Field identification & locations

Identify by its perfect cubic form, characteristic striations on crystal faces, and high hardness (it cannot be scratched by a copper cent). Common locations include Spain, Italy, Peru, and the USA.