Jamesonite
Image: Robert M. Lavinsky (CC BY-SA 3.0)
Mineral NameJamesonite
Chemical FormulaFePb4Sb6S14
Mohs Hardness2.5
Crystal Systemmonoclinic
Lustermetallic
Streak Colorgrayish black
Cleavagegood on {001}
Fractureuneven
Specific Gravity5.5
Colorslead-gray, steel-gray, iron-black
Transparencyopaque
Type LocalityConcepción del Oro, Zacatecas, Mexico
Mineral GroupSulfosalts
Usesore of lead, ore of antimony, collector's item
Associated Mineralsgalena, sphalerite, pyrite, quartz, siderite, stibnite, tetrahedrite
Rarityuncommon
Description
The image displays a specimen of Jamesonite composed of numerous fine, needle-like crystals, exhibiting a metallic lead-gray luster and forming a dense, felted mass.
Geological Context
Jamesonite typically forms in low- to medium-temperature hydrothermal veins, often found in association with other lead, antimony, and sulfur-bearing minerals.
