Wiktionary
arsenolite
n. (context mineral English) A mineral form of arsenic trioxide.
Wikipedia
Arsenolite
Arsenolite is an arsenic mineral, chemical formula AsO. It is formed as an oxidation product of arsenic sulfides. Commonly found as small octahedra it is white, but impurities of realgar or orpiment may give it a pink or yellow hue. It can be associated with its dimorph claudetite (a monoclinic form of AsO) as well as realgar (AsS), orpiment (AsS) and erythrite, Co(AsO)ยท8HO.