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: Indistinct; Specific Gravity: 4.8-5.0

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

Identified May 16, 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: Indistinct; Specific Gravity: 4.8-5.0

Formation & geological history

Formed in high and low-temperature hydrothermal veins, as an accessory mineral in igneous rocks, and in sedimentary rocks through metamorphic or reductive processes. It is found in geological settings ranging from Precambrian to recent times.

Uses & applications

Historically used as a source of sulfur and sulfuric acid. Today, it is used for jewelry (marcasite jewelry), as an ornamental stone, and sometimes as an ore of iron or gold (auriferous pyrite).

Geological facts

Commonly known as Fool's Gold because its color and high density lead novice gold seekers to mistake it for the real thing. It can actually spark when struck against steel, which was used in wheel-lock rifles in the 16th century.

Field identification & locations

Identify in the field by its brassy color, hardness (it can scratch glass), and its greenish-black streak when rubbed on a porcelain plate (real gold has a yellow streak). Commonly found in Spain, Italy, Peru, and various regions of the US like Colorado and Arizona.