mineral

Pyrite on Quartz matrix

Iron Disulfide (FeS2) on Silicon Dioxide (SiO2)

Hardness: 6-6.5 (Pyrite), 7 (Quartz); Color: Brass-yellow metallic Pyrite on milky white Quartz; Luster: Metallic (Pyrite)/Vitreous (Quartz); Crystal Structure: Isometric (Pyrite cubes/pyritohedrons) and Hexagonal (Quartz); Cleavage: Indistinct; Specific Gravity: 4.9-5.2.

Hardness: 6-6
Color: Brass-yellow metallic Pyrite on milky white Quartz
Luster: Metallic (Pyrite)/Vitreous (Quartz)

Identified March 18, 2026More mineral →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Formed in hydrothermal veins through the cooling of mineral-rich hot fluids or as a secondary mineral in sedimentary and metamorphic environments. These minerals can range in age from millions to billions of years depending on the host rock formation.

Uses & applications

Primarily used as decorative display specimens for collectors and in jewelry (as 'marcasite'). Pyrite is also a minor ore of sulfur and was historically used to create sparks for firearms.

Geological facts

Pyrite is famously known as 'Fool's Gold' because its metallic luster and brassy hue often led novice prospectors to mistake it for real gold. Unlike gold, it is brittle and will shatter rather than flatten when struck.

Field identification & locations

Identify in the field by its brassy color, cubic crystal habit, and blackish-green streak on a porcelain plate. It is found globally, with significant deposits in Spain, Peru, and the USA (Colorado/Arizona). Collectors look for well-defined crystal faces.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral

Epidote

Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)

mineral