Rosell Minerales

Very interesting blue-violet to lavender aggregates of johillerite, on matrix, and accompanied by black hematite crystals. Johillerite is a extremelly rare arsenate with sodium, copper and magnesium+zinc: Na(Mg,Zn)3Cu(AsO4)3. Only three localities worldwide: Tsumeb (TL), slags from Genna (Germany) and the Tolbachik volcano in Kamchatka. Johillerite forms a continuous solid-solution system with badalovite and nickenichite. Johillerite samples were obtained from the fumaroles of the North Breach of the great fissure Tolbachik volcano eruption (1975-1976). Cone took 44 days to form.