Stibnite
Image: Islam90 (CC BY-SA 4.0)
Mineral NameStibnite
Chemical FormulaSb₂S₃
Mohs Hardness2
Crystal Systemorthorhombic
Lustermetallic
Streak Colorgray to black
Cleavageperfect on {010}
Fracturesubconchoidal to uneven
Specific Gravity4.6
Colorslead-gray, dark gray, black
Transparencyopaque
Type LocalityIchinokawa (Japan), Xikuangshan (China), Baia Mare (Romania)
Mineral GroupSulfides
Usesore of antimony, flame retardants, pigments, cosmetics (historically), collector
Associated Mineralsquartz, calcite, barite, cinnabar, realgar, orpiment
Raritycommon
Description
This image displays a microscopic section of stibnite, showing dark gray to black grains embedded in a lighter matrix, characteristic of its metallic appearance under magnification. Macroscopically, stibnite typically forms slender, prismatic to acicular crystals, often in radiating aggregates.
Geological Context
Stibnite commonly forms in low-temperature hydrothermal veins, often associated with hot springs and volcanic activity. It can also be found in replacement deposits and rarely in pegmatites.
