Arsenopyrite
Image: Andrew Silver (Public domain)
Mineral NameArsenopyrite
Chemical FormulaFeAsS
Mohs Hardness5.5
Crystal Systemmonoclinic
Lustermetallic
Streak Colordark grayish-black
Cleavagedistinct on {101}
Fractureuneven to conchoidal
Specific Gravity6
Colorssilvery white, steel gray
Transparencyopaque
Type LocalityWorldwide, notable localities include Freiberg (Germany), Cornwall (England), various gold districts in Canada and the USA.
Mineral GroupSulfides
Usesore of arsenic, minor ore of gold, collector specimens
Associated Mineralsgold, pyrite, chalcopyrite, sphalerite, galena, quartz, tourmaline
Raritycommon
Description
The image displays a silvery-white to steel-gray metallic mineral, likely arsenopyrite, exhibiting a crystalline habit, possibly prismatic or tabular, with a pen providing scale.
Geological Context
Arsenopyrite commonly forms in high-temperature hydrothermal veins, contact metamorphic deposits, and pegmatites, often serving as an indicator mineral for gold deposits.
