Stibnite, the primary ore of Antimony, is a sulfide mineral. It occurs in hydrothermal veins, hot-spring deposits, and replacement deposits that form at low temperatures (up to 400°F/200°C). It's named after the Latin stibium, which is the old name of the element Antimony (Sb). Natural Stibnite crystals can be long, slender prismatic, lustrous, and shiny, often with a sword-like in appearance, but occasionally can tarnish with a dull or iridescent coating.
 
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* Photos show all sides.
* Sizes, shapes and colors my vary due to being a natural stone, being hand-carved and/or difference in computer monitors.