Millosevichite is a rare sulfate mineral with the chemical formula Al2(SO4)3. Aluminium. It forms finely crystalline and often porous masses.
It was first described in 1913 for an occurrence in Grotta dell'Allume, Porto Levante , Aeolian Islands. 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 It occurs with native sulfur , letovicite and boussingaultite