(Fortullino, Rosignano Marittimo, Livorno, Toscana, Italia)
The mineral is localized in a magnesite occurrence. Melanophlogite is not the only mineral here, but other minerals of the area are represented by dolomite, magnesite, cinnabar, kutnahorite.
The origin is due to carbonatic alteration of original serpentines that has brought to the formation of carbonatic rocks Mg rich and segregation of siliceous phase as melanophlogite and opal.
Refs.:
Grassellini Troysi, M. & Orlandi, P. (1972): Sulla melanoflogite del Fortullino (Livorno). Atti della Società Toscana di Scienze Naturali, Memorie, Serie A: Processi Verbali, 79, 245-250.
Gallo, S. (1974): Melanophlogite, a new and interesting find. Mineralogical Record, 5(5), 207-208.
Henderson, B. (1981): Microminerals. Mineralogical Record 12(6), 383.
Lenzi, A. (1996): La melanoflogite di località Fortullino. Informatore. Giornale del Museo di Storia Naturale Rosignano Solvay, 1, 10-13.