Magganasite

magganasite

No images

Formula: CuFe3+3O(AsO4)3
Valence: Cu2+Fe3+3O(As5+O4)3
Anhydrous arsenate of copper and iron
Crystal system: Triclinic
Specific gravity: 4.708 calculated
Streak: Yellow
Colour: Golden- or red- brown to brownish yellow, brown or reddish brown
Environments

Fumeroles

Magganasite is a new mineral, approved in 2021 and to date (January 2026) reported only from the type locality.

Localities

At the type locality, the Arsenatnaya fumarole, Second scoria cone, Northern Breakthrough, Great Fissure eruption, Tolbachik Volcanic field, Milkovsky District, Kamchatka Krai, Russia, magganasite was found as prismatic crystals up to 0.2 mm long and up to 0.04 mm thick typically assembled in clusters up to 1 mm across in material collected from hot fumerole (the temperature measured during sampling varied from 350 to 400°C) pockets situated 1 to 1.5 m below the day surface. Associated minerals include alarsite, calciojohillerite, cassiterite, euchlorine, fedotovite, hematite, johillerite, lammerite, langbeinite, paralammerite, sanidine, tenorite and wulffite (Mindat).

Back to Minerals