What is "millosevichite"

n. (context mineralogy English) A rare mineral with the chemical formula Al₂(SO₄)₃, forming white to yellowish cryptocrystalline masses.

Millosevichite is a rare sulfate mineral with the chemical formula Al(SO). Aluminium is often substituted by iron. It forms finely crystalline and often porous masses.

It was first described in 1913 for an occurrence in Grotta dell'Allume, Porto Levante, Vulcano Island, Lipari, Aeolian Islands, Sicily. It was named for Italian mineralogist Federico Millosevich (1875–1942) of the University of Rome.

The mineral is mainly known from burning coal dumps, acting as one of the main minerals forming sulfate crust. It can be also found in volcanic solfatara environments. It occurs with native sulfur, sal ammoniac, letovicite, alunogen and boussingaultite.