mineral

Pyrite

Iron Sulfide (FeS2)

Hardness: 6-6.5 on Mohs scale; Color: Pale brass-yellow; Luster: Metallic; Crystal Structure: Isometric (often cubic or pyritohedral); Cleavage: Poor/Indistinct; Specific Gravity: 4.8–5.0

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

Identified March 23, 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; Luster: Metallic; Crystal Structure: Isometric (often cubic or pyritohedral); Cleavage: Poor/Indistinct; Specific Gravity: 4.8–5.0

Formation & geological history

Forms in a wide range of geological environments including hydrothermal veins, as an accessory mineral in igneous rocks, in contact metamorphic rocks, and in sedimentary rocks such as shale and coal. It forms through the precipitation of iron and sulfur in oxygen-poor environments.

Uses & applications

Primary source of sulfur and sulfuric acid used in industry. Occasionally used in jewelry (as 'marcasite'); also used in early radio receivers (crystal radios) and as a grounding stone in metaphysical collecting.

Geological facts

Commonly nicknamed 'Fool's Gold' due to its resemblance to precious metal. Historically, it was used to strike sparks for early firearms (wheellocks) and starting fires. It is the most common sulfide mineral found on Earth's crust.

Field identification & locations

Identify in the field by its brittle nature (gold is malleable), cubic crystal habits, and its greenish-black streak when rubbed on a porcelain plate. Found worldwide with major deposits in Spain (Rio Tinto), Italy, and the USA (Arizona, Colorado).