Druzy Pyrite (Iron Pyrite)
Pyrite (Iron Bisulfide) · Mineral Specimen / Decorative Stone
Crystal System
Cubic (Isometric); habit in this specimen is druzy (a coating of tiny crystals) on a massive matrix.
Mineral Group
Sulfides
Chemical Formula
FeS2 (Iron Disulfide)
Formation Process
Hydrothermal or Sedimentary: Forms through the precipitation of iron and sulfur from hot mineral-rich fluids or in oxygen-poor sedimentary environments.
About This Crystal
The specimen features a central pocket of druzy pyrite, characterized by many tiny, sparkling cubic or pyritohedral faces. The surrounding matrix is duller, likely containing oxidized iron minerals (limonite/goethite). The color is metallic brass-yellow where fresh, with a duller brownish-grey exterior.
Physical Characteristics
Color: Pale brass-yellow to golden. Streak: Greenish-black to brownish-black. Luster: Metallic. Cleavage: Indistinct. Fracture: Conchoidal to uneven. Specific Gravity: 4.9–5.2. Fluorescence: None.
Optical Properties
Opaque mineral. Luster is metallic and highly reflective on minute crystal faces, creating a 'sparkle' effect. No refractive index or birefringence as it is not transparent.
Hardness & Durability
Origin Region
Globally distributed; notable druzy specimens from Peru, Spain, Italy, and the USA (Missouri/Illinois). Found in sedimentary rocks and hydrothermal veins.
Hardness & Durability
Mohs Hardness: 6–6.5. Toughness: Brittle. Generally stable but can be prone to 'pyrite disease' (oxidation) if exposed to high humidity.
Care & Maintenance
Keep dry and away from high humidity to prevent oxidation. Clean with a soft, dry brush or compressed air. Avoid water, steam, and ultrasound cleaning which can damage the delicate druzy surface.
Rarity & Value
Common. As a druzy specimen, value is determined by the coverage and 'sparkle' of the crystals. Generally inexpensive and widely available for collectors.
Special Characteristics
Displays a druzy texture with high metallic luster. Notable for its 'Fool's Gold' appearance and its ability to create sparks when struck against steel.
Lore & History
Commonly known as 'Fool's Gold.' Historically used by Native Americans for mirrors and as a spark-inducer for fire-starting. Conventionally associated with the solar plexus chakra, wealth, and protection in traditional lore.