Paragenesis of akatoreite and ganophyllite in the manganiferous rocks of the Haste field, Norberg ore district, central Sweden.

The chemistry, texture and mode of occurrence of secondary akatoreite and ganophyllite in intercalations of manganiferous rocks in K-rich acid metavolcanics from the Haste field are described. The average of 8 microprobe analyses of akatoreite gave SiO₂ 36.9, TiO₂ 0.1, Al₂O₃ 6.2, FeO 0.9, MnO 44.2, MgO 0.8, CaO 0.2, H₂O (diff.) 10.7, = 100.0. The average of 5 analyses of ganophyllite gave SiO₂ 40.1, TiO₂ 0.2, Al₂O₃ 6.8, FeO 0.6, MnO 34.5, MgO 0.6 CaO 1.0, Na₂O 1.0, K₂O 3.1, H₂O (diff.) 12.1, = 100.0. These manganiferous rocks are represented by four major parageneses, primarily containing urbanite, braunite, richterite, rhodonite, hematite, andradite and spessartine; the secondary akatoreite and ganophyllite have commonly replaced richterite and urbanite.-R.A.H.