Stibnite
Image: Ivar Leidus (CC BY-SA 4.0)
Mineral NameStibnite
Chemical FormulaSb2S3
Mohs Hardness2
Crystal Systemorthorhombic
Lustermetallic
Streak Colorlead gray to black
Cleavageperfect on {010}
Fracturesubconchoidal to uneven
Specific Gravity4.6
Colorslead gray, dark gray, black, sometimes iridescent
Transparencyopaque
Type LocalityHerja mine, Maramureș, Romania
Mineral GroupSulfides
Usessource of antimony, collector specimens
Associated Mineralsquartz, calcite, barite, cinnabar, galena, sphalerite
Rarityuncommon
Description
This specimen features a radiating cluster of slender, elongated, acicular crystals of stibnite, exhibiting a brilliant metallic luster and a dark lead-gray color.
Geological Context
Stibnite typically forms in low-temperature hydrothermal veins, often associated with other sulfide minerals, and can be found in hot spring deposits.
