Dimorphite, chemical name arsenic sesquisulfide (As
4S
3), is a very rare orange-yellow arsenic sulfide mineral. In nature, dimorphite forms primarily by
deposition in volcanic
fumaroles at temperatures of 70–80 °C (158–176 °F). Dimorphite was first discovered in such a fumarole near Naples, Italy in 1849 by the mineralologist
Arcangelo Scacchi (1810–1893). Since its discovery, dimorphite has been found in the Alacrán silver mine near
Copiapó,
Chile.
It has also been reported from
Cerro de Pasco,
Peru, and the Lavrion District Mines in
Attica,
Greece.
[
]
Properties and applications
Dimorphite has two crystal forms, Α- and Β-. This property gives rise to its name, which comes from the Greek for "two" and "form." Dimorphite transitions between its α- and β- forms at around 130 °C (266 °F).[Wiberg, Egon, Nils Wiberg, and Arnold Frederick Holleman. ''Inorganic Chemistry.'' San Diego: Academic Press, 2001.]
Initial research indicates the possibility of using synthetic dimorphite in the development of gas sensor
A gas detector is a device that detects the presence of gases in an area, often as part of a safety system. A gas detector can sound an alarm to operators in the area where the leak is occurring, giving them the opportunity to leave. This type of ...
s,[
] due to the semiconductive properties of dimorphite.
References
{{Reflist
Arsenic minerals
Sulfide minerals
Orthorhombic minerals
Minerals in space group 62