Pyrite
Pyrite · Mineral Specimen / Industrial Mineral
Crystal System
Cubic (Isometric); typically occurs as cubes, pyritohedrons, or octahedrons; massive or granular habits are also common.
Mineral Group
Sulfides
Chemical Formula
FeS2
Formation Process
Highly versatile; forms in magmatic segregations, hydrothermal veins, contact metamorphic deposits, and as an authigenic mineral in sedimentary rocks.
About This Crystal
The specimen shows a small, highly reflective metallic crystal embedded in a gossan-like or iron-stained matrix. It exhibits a pale brass-yellow color with a strong metallic luster and appears to have a cubic or modified isometric form.
Physical Characteristics
Color: Brass-yellow; Streak: Greenish-black to brownish-black; Cleavage: Indistinct; Fracture: Conchoidal to uneven; Specific Gravity: 4.9–5.2; Weakly magnetic when heated; Brittle tenacity.
Optical Properties
Opaque; Metallic luster; High reflectivity; Isotropic (singly refractive); No pleochroism or birefringence.
Hardness & Durability
Origin Region
Worldwide; notable localities include Peru (Huanzala), Spain (Rio Tinto), Italy (Elba), and the USA (Arizona, Colorado).
Hardness & Durability
Mohs Hardness: 6–6.5. Relatively brittle and prone to shattering upon impact. Known as 'Fool's Gold' because it is harder/more brittle than real gold.
Care & Maintenance
Keep in a dry environment to avoid 'pyrite disease' (oxidation into iron sulfates). Clean with a soft, dry brush; avoid water and high humidity which can trigger decomposition.
Rarity & Value
Very common and abundant. Value is generally low for small specimens, though large, well-formed museum-quality crystals can command high prices. Rarely treated.
Special Characteristics
Striated crystal faces are common (not clearly visible in this image); exhibits striking metallic reflection; can act as a semiconductor.
Lore & History
Historically used by Native Americans as mirrors and in fire-starting. Traditionally associated with the Solar Plexus chakra, believed to represent wealth, protection, and willpower.