Godovikovite

Godovikovite is a rare mineral of the chemical formula written as (NH₄)Al(SO₄)₂. Al can partially be substituted by Fe. Hydratation of godovikovite gives the ammonium alum, tschermigite. The mineral forms cryptocrystalline, often porous, masses, usually of white colour. Single crystals are very small hexagonal blades. Typical environment for godovikovite are burning coal sites (mainly dumps). There the mineral acts, together with millosevichite, as one of the main components of so-called sulfate crust.