Jamesonite with quartz Locality : Anita Mine - Huaron Peru - (View 4cm). — Photo: Didier Descouens · CC BY-SA 3.0
Jamesonite
Also known as: Feather ore.
A lead-iron-antimony sulfosalt — 'feather ore' — famous for its fibrous, plumose gray masses.
Intro adapted from Wikipedia (CC BY-SA).
Jamesonite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula Pb₄FeSb₆S₁₄.
It crystallizes in the monoclinic crystal system (space group P2_1/a).
Key properties: Mohs hardness 2–2.5; specific gravity 5.63; typically gray; grayish-black streak; Metallic luster.
IMA symbol Ja, grandfathered status — known before the IMA’s founding, named in 1825.
Typically a late-stage hydrothermal mineral in Pb–Ag–Zn veins formed at low to medium temperatures.
It is found associated with Other lead sulfosalts, pyrite, sphalerite, galena, tetrahedrite, stibnite, quartz, siderite, calcite, dolomite, rhodochrosite.
In honor of Robert Jameson (1774–1854), Scottish mineralogist, Edinburgh, Scotland, who first described the mineral.
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