Comments : This arsenopyrite shows good crystals and good
luster. It formed a perfect sphere with curved serated crystals.
Extremely aesthetic. I procured this from a Chinese dealer at the St
Marie Aux Mines show of 2006. The specimen comes from Yauganxian
mine, Hunan, China
Arsenopyrite is an iron arsenic sulfide (FeAsS). It is a hard (Mohs
5.5-6) metallic, opaque, steel grey to silver white mineral with a
relatively high specific gravity of 6.1. When dissolved in nitric
acid, it produces sulfur. When arsenopyrite is heated, it becomes
magnetic, and gives off toxic fumes.
Arsenopyrite contains about 46% arsenic and is a principle ore of
arsenic along with orpiment.
Arsenopyrite crystallizes in the monoclinic crystal system and often
shows prismatic crystal or columnar forms with striations and
twinning common. Arsenopyrite may be referred to in older references
as orthorhombic, but has been shown to be monoclinic.
The crystal habit, hardness, density, and garlic odor when struck are
diagnostic. Arsenopyrite in older literature may be referred to as
mispickel, a name of German origin