Arsenopyrite is an iron arsenic sulfide (FeAsS). It is a hard (Moh's 5.5-6) metallic, opaque, steel grey to silver white mineral with a relatively high specific gravity of 6.1. Arsenopyrite contains about 46% arsenic and is a principle ore of arsenic. 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 odor (garlic) when struck are supposedly diagnostic. In chemistry, a sulfide (sulphide in British and Canadian English) is a chemical compound or combination of sulfur with an oxidation number of -2, with another chemical element or a radical thereof. ... Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer. ... Relative density (also known as specific gravity) is a measure of the density of a material. ... General Name, Symbol, Number arsenic, As, 33 Chemical series metalloids Group, Period, Block 15, 4, p Appearance metallic gray Atomic mass 74. ... In crystallography, the monoclinic crystal system is one of the 7 lattice point groups. ... In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... In bodybuilding, striations are the tiny grooves of muscle across major muscle groups characteristic of a well-developed body. ... In crystallography, the orthorhombic crystal system is one of the 7 lattice point groups. ...

Various transition group metals occur in arsenopyrite as subtitutes for iron. A cobalt rich variety is known as danaite. Arsenopyrite also can contain significant amounts of gold. In telecommunication, a transition is the change from one signal state to another signal state. ... General Name, Symbol, Number cobalt, Co, 27 Chemical series transition metals Group, Period, Block 9 , 4, d Density, Hardness 8. ... General Name, Symbol, Number gold, Au, 79 Chemical series transition metals Group, Period, Block 11, 6, d Appearance metallic yellow Atomic mass 196. ...

Arsenopyrite is found in high temperature hydrothermal veins, in pegmatites, and in areas of contact metamorphism or metasomatism. Hydrothermal circulation in the oceans is the passage of the water through mid-ocean Ridge (MOR) systems. ... Pegmatite is a very coarse-grained igneous rock that has a grain size of 20 mm or more; such rocks are referred to as pegmatitic. ... Metamorphism can be defined as the mineralogical, chemical and crystallographic changes in a solid-state rock, i. ... Metasomatism is a geologic process where metamorphism causes an alteration in a mineral or rock mass that involves a chemical change of the substance with the addition of material, as when chrysolite (olivine) is converted to serpentine basically by the addition of water. ...

The arsenopyrite group of minerals includes the following rare minerals:

• Clinosafflorite: (Co,Fe,Ni)AsS
• Gudmundite: FeSbS
• Glaucodot, Danaite, or Alloclasite: (Fe,Co)AsS
• Iridarsenite: (Ir,Ru)AsS
• Osarsite or Ruarsite: (Os,Ru)AsS or (Ru,Os)AsS

References

• Dana's Manual of Mineralogy ISBN 0471032883
• mindat.org
• Minerals.net