Arsenopyrite can be found worldwide, but crystals of good quality are more limited. Excellent specimens of Arsenopyrite are found in Asia at the Yaogangxian Mine, Hunan Province, China; the Huanggang Mine, Inner Mongolia, China; and the Obira Mine on Kyushu Island, Japan.
Important European localities for Arsenopyrite include Panasqueira, Portugal; Freiberg, Saxony, Germany; Trepca, Kosovo (former Yugoslavia); and several of the ore
deposits in the Cornwall area in England. In South America, fine Arsenopyrite crystals have come from Potosi, Bolivia; and the Pachapaqui District, Ancash Dept., Peru. Mexico also contains several notable occurrences, especially the Santa Eulalia district, Chihuahua; and Concepcion del Oro, Zacatecas.
In the U.S., Arsenopyrite localities include Mount Mica, Oxford Co., Maine; Roxbury, Litchfield Co., Connecticut; Lewis, Essex Co., New York; Franklin, Sussex Co., New Jersey; Leadville, Lake Co., Colorado; and the Cleveland mine, Stevens Co., Washington. Fine specimens were once found Carmel, Putnam Co., New York. The cobalt-rich variety, Danaite
, comes from Franconia, Grafton Co., New Hampshire. In Canada, Arsenopyrite is found in the Cobalt area, Timiskaming District, Ontario; and in the Nickel Plate Mine, British Columbia.