The sulfarsenide minerals are a subgroup of the sulfide minerals which include arsenic replacing sulfur as an anion in the formula.Klein, Cornelis and Cornelius S. Hurlbut, 1985, Manual of Mineralogy, 20th ed., John Wiley and Sons, New York, p. 290 Antimony and bismuth may occur with or in place of the arsenic as in ullmannite. The chemical formula of a sulfarsenide looks like a sulfosalt, however the structures are distinctly different. In sulfosalts the arsenic replaces a metal ion.
The sulfarsenides are grouped with the sulfides in both the Dana and Strunz mineral classification systems.http://webmineral.com/dana/II-2.shtml#2.1 Webmineral Danahttp://webmineral.com/strunz/II.shtml Webmineral Strunz
Examples include:http://rruff.info/about/downloads/AM93_1183.pdf Hexiong Yang and Robert T. Downs, Crystal structure of glaucodot, (Co,Fe)AsS, and its relationships to marcasite and arsenopyrite, American Mineralogist, Volume 93, pages 1183–1186, 2008Palache, C., H. Berman, and C. Frondel (1944) Dana’s system of mineralogy, (7th edition), v. I, p. 296
Arsenopyrite group: Arsenopyrite Glaucodot Gudmundite Lautite Alloclasite Cobaltite group Cobaltite Gersdorffite Ullmannite
References