alunogen
/əˈl(j)uːnədʒ(ə)n/Mineralogy
noun
A mineral consisting of hydrated aluminium sulphate, typically occurring as masses of feathery or fibrous crystals.
- Chemical formula: Al2(SO4)3·17H2O. Crystal system: triclinic..
Origin
Mid 19th century. From French alunogène from alun + -ogène; so called because it can be converted into alum by simple chemical means.