User:Dwwashburn/Dimorphite

Dimorphite (chemical name tetraarsenic trisulfide) is a very rare orange-yellow chalcogenide mineral, related to realgar. In nature, dimorphite forms primarily by deposit in volcanic fumaroles at temperatures of 70&deg;-80&deg;C (158&deg;F-176&deg;F). Dimorphite was first discovered in a such a fumarole near Naples, Italy in 1849 by the mineralologist Arcangelo Scacchi (1810-1893). Since its discovery, dimorphite has only been found elsewhere in the Alacr&aacute;n silver mine near Copiap&oacute;, Chile. However, dimorphite can be synthesized by melting arsenic and sulfur together in the proper molar ratios in vacuum.

Interesting Properties and Applications
Dimorphite has two crystal forms, &alpha;- and &beta;-. This property gives rise to its name, which comes from the Greek for "two" and "form." Dimorphite transitions between its &alpha;- and &beta;- forms at around 130&deg;C (266&deg;F).

Initial research done by professors from the Technical University of Moldova and the Universität der Bundeswehr München indicates the possibility of using dimorphite in the development of gas sensors, due to the semiconductive properties of dimorphite. Dimorphite also reacts with sulfur in carbon disulfide (CS2) to form tetraarsenic tetrasulfide (realgar), a major source of arsenic and a component in some fireworks.