Felsőbányaite or basaluminite is a hydrated aluminium sulfate mineral with formula: Al4(SO4)(OH)10·4H2O.

It is a rare white to pale yellow mineral which typically occurs as globular masses and incrustations or as minute rhombic crystals.

[3][2] It occurs as a weathering product under acidic conditions associated with pyrite or marcasite decomposition.

Associated minerals include hydrobasaluminite, hydroargillite, meta-aluminite, allophane, gibbsite, gypsum and aragonite.

[3] Felsőbányaite was first described in 1853 for an occurrence in the Baia Sprie mine, Baia Sprie (Felsőbánya), Maramureș County, Romania, and named for the locality.