[mis-pik-uh
l] 
[ahr-suh-noh-pahy-rahyt, ahr-sen-uh-] | a common mineral, iron arsenic sulfide, FeAsS, occurring in silver-white to steel-gray crystals or masses: an ore of arsenic. |
| ar·se·no·py·rite (är'sə-nō-pī'rīt) n. A silver-white to gray arsenic ore, essentially FeAsS. Also called mispickel. |
| mis·pick·el (mĭs'pĭk'əl) n. See arsenopyrite. [Obsolete German Misspickel, from earlier Misspült, Misspückel.] |
mispickel
an iron sulfoarsenide mineral (FeAsS), the most common ore of arsenic. It is most commonly found in ore veins that were formed at high temperatures, as at Mapimi, Mex.; Butte, Mont.; and Tunaberg, Swed. Arsenopyrite forms monoclinic or triclinic crystals with an orthorhombic shape; the physical appearance of these crystals is seldom an accurate method for determining their symmetry. A series of minerals in which cobalt partially replaces iron is called cobaltian arsenopyrites; those in which the Co:Fe ratio lies between 1:2 and 6:1 are called glaucodot (see also cobaltite). Weathering alters these sulfides to arsenates: arsenopyrite to scorodite, and glaucodot to erythrite. For detailed physical properties, see sulfide mineral (table)
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