[1] : The Collaborative International Dictionary of English v.0.48

mispickel \mispick"el\, n. g. min.
   arsenical iron pyrites; arsenopyrite.
   1913 webster

[2] : The Collaborative International Dictionary of English v.0.48

arsenopyrite \ar`senopyr"ite\, n. arsenic + pyrite. min.
   a mineral of a tin-white color and metallic luster,
   containing arsenic, sulphur, and iron; -- also called
   arsenical pyrites and mispickel.
   1913 webster
see also:
arsenical pyrites mispickel 

[3] : WordNet (r) 2.0

mispickel
     n : a silver-white or gray ore of arsenic syn: arsenopyrite
see also:
arsenopyrite 

Mispickel >> M Words
Mispickel, definition of term: Mispickel
mispickel_pag1.html