Boji Stone
Marcasite / Pyrite Concretion · Mineral Specimen
Crystal System
Orthorhombic (Marcasite) or Cubic (Pyrite) with massive/concretionary habit
Mineral Group
Sulfides
Chemical Formula
FeS2
Formation Process
Sedimentary diagenesis, forming concretions in sandstone or shale beds
About This Crystal
Small, dark brownish-grey to black spherical concretion with a somewhat rough, textured surface, often showing patches of oxidation or rust.
Physical Characteristics
Dark brown to black body color, brownish-black streak, conchoidal to uneven fracture, specific gravity around 4.8 to 5.0, brittle tenacity, metallic luster where polished or exposed, opaque.
Optical Properties
Opaque with metallic luster, isotropic or anisotropic depending on exact mineral phase (pyrite vs marcasite).
Hardness & Durability
Origin Region
Kansas, USA (specifically the Navajo Reservation)
Hardness & Durability
Mohs hardness of 6 to 6.5, fairly brittle, sensitive to moisture due to potential oxidation of iron sulfides (marcasite disease).
Care & Maintenance
Keep completely dry; avoid water cleaning to prevent rusting and deterioration; store in a dry, low-humidity environment.
Rarity & Value
Common, widely sold as metaphysical stones from specific localities in the American Midwest, typically inexpensive.
Special Characteristics
Often marketed in pairs (male and female) with magnetic or energy-balancing claims, though scientifically they are standard iron sulfide concretions.
Lore & History
Popular in New Age and crystal healing practices for grounding, energy alignment, and balancing yin/yang energies, though these are strictly traditional beliefs without scientific backing.