pharmacosiderite

from The Collaborative International Dictionary of English v.0.48

Pharmacosiderite \Phar`ma*co*sid"er*ite\, n. [Gr. fa`rmakon
   drug, poison + E. siderite.] (Min.)
   A hydrous arsenate of iron occurring in green or yellowish
   green cubic crystals; cube ore.
   [1913 Webster]