Pyrite
Pyrite (Iron Disulfide) · Mineral Specimen / Industrial Mineral
Crystal System
Cubic (Isometric); commonly found in cubes, pyritohedrons, or as massive, granular, or botryoidal forms.
Mineral Group
Sulfides
Chemical Formula
FeS2
Formation Process
Primarily Hydrothermal; forms from iron-bearing fluids in high-temperature veins, but also common as an accessory mineral in igneous and sedimentary rocks via chemical precipitation.
About This Crystal
Opaque with a distinct metallic luster. Color is typically brass-yellow to pale gold, often tarnishing to a darker brown. It features brittle, flat-faced crystals or granular aggregates within a rocky matrix.
Physical Characteristics
Color: Brass-yellow; Streak: Greenish-black to brownish-black; Cleavage: Indistinct; Fracture: Conchoidal to uneven; Specific Gravity: 4.9–5.2; Fluorescence: Generally none.
Optical Properties
Opaque (singly refractive); very high reflectivity; no pleochroism or birefringence due to its cubic nature and opacity.
Hardness & Durability
Origin Region
Spain (Rio Tinto), Peru (Huaron), Italy (Elba), and the USA (Colorado). Forms in hydrothermal veins, metamorphic rocks, and sedimentary environments.
Hardness & Durability
Mohs Hardness: 6–6.5; Brittle toughness; sensitive to high heat which can release sulfur dioxide; generally stable but can 'rot' if exposed to high humidity and oxygen (pyrite disease).
Care & Maintenance
Keep dry to prevent oxidation; clean with a soft brush and avoid water or ultrasonic cleaners. Store in a low-humidity environment to prevent chemical degradation.
Rarity & Value
Common; price is generally low for small specimens ($5-$20), though large, perfect crystal cubes or unique formations can command higher collector prices.
Special Characteristics
Known as 'Fool's Gold' due to its metallic luster and gold-like color. Can produce sparks when struck against steel (striking fire).
Lore & History
Historically used by ancient civilizations for fire-starting and mirrors. Symbolically associated with the Solar Plexus chakra, believed to represent abundance, protection, and willpower in traditional lore.