新潟縣北越,臺灣金瓜石兩礦山に於けるルゾナイトの産出状態

抄録

The Hoku-etu copper deposits are found on, a disected wall and bottom of an extinct volcano, named Sumon-daké. They consist of fine-grained aggregates of quartz, pyrite and luzonite, sometimes with abundant sulphur. Enargite and barite are also found in many druses. The ores seem to be partly sofataric and partly metasomatic in origin. The luzonite, chemically analysed by J. Kitahara, consists essentially of Cu₃AsS₄, but its X-ray pattern, obtained by T. Takeuti, is not similar to that of enargite crystals but corresponds to that of famatinite, obtained by Frebold. Thus the dimorphic relation between enargite and luzonite, which has long been discussed by Weisbach, Moses, Frebold, De Jong, Schneiderhöhn-Ramdohr and Harcourt, among others, is ascertained. Similar conclusion been arrived at also by H Sawada, according to his personal communication.
Luzonite from Kinkaseki occurs in a quite similar association of quartz, pyrite, barite and enargite, sometimes with sulphur. Negative pseudomorphs of luzonite after enargite are also found, indicating that the former is stable while the latter is unstable against some solutions even at same temperatures. Fresh luzonite is found also covered by chrysocolla, suggesting its stableness at oxidizing conditions.