Molecule structure of Arsenopyrite (CAS NO.1303-18-0):

Molecular Formula: AsFeS 
Synonyms: Arsenomarcasite ; Dalarnite ; Mispickel ; Arsenopyrite (FeAsS)

Arsenic and its compounds are on the Community Right-To-Know List.

Poison by intravenous route. When heated to decomposition it emits very toxic fumes of As and SO_x.

OSHA PEL: TWA 0.01 mg(As)/m³
ACGIH TLV: BEI: 35 μ (As)/L inorganic arsenic and methylated metabolites in urine
NIOSH REL: (Arsenic, Inorganic) CL 2 µg(As)/m³/15 M

 Arsenopyrite (CAS NO.1303-18-0) is highly toxic. It is flammable. It will produce toxic sulfur oxides and arsenic fumes when buring. So the storage environment should be ventilate, low-temperature and dry. Keep Arsenopyrite (CAS NO.1303-18-0) separate from raw materials of food. Arsenopyrite is a hard (Mohs 5.5-6) metallic, opaque, steel grey to silver white mineral with a relatively high specific gravity of 6.1. Arsenopyrite becomes magnetic and gives off toxic fumes, when it is heated. It releases elemental sulfur, when it dissolved in nitric acid. It is a principal ore of arsenic with 46% arsenic content, arsenopyrite, along with orpiment. When deposits of arsenopyrite become exposed to the atmosphere, usually due to mining, the mineral will slowly oxidize, converting the arsenic into oxides that are more soluble in water, leading to acid mine drainage. The crystal habit, hardness, density, and garlic odor when struck are diagnostic. Arsenopyrite also can be associated with significant amounts of gold. Consequently it serves as an indicator of gold bearing reefs. Many arsenopyrite gold ores are refractory, i.e. the gold is not easily liberated from the mineral matrix. Arsenopyrite is found in high temperature hydrothermal veins, in pegmatites, and in areas of contact metamorphism or metasomatism.