"Alunite is a hydrated aluminium potassium, sulfate mineral, formula KAl3(SO4)2(OH)6. It was first observed in the 15th century at Tolfa, near Rome, where it is mined for the manufacture of alum." [Wikipedia]
Comments
Alunite dust causes pneumoconiosis in 26-week intermittent inhalation studies (unspecified mammal species); [RTECS] See "Aluminum potassium sulfate."