alunite(redirected from Alumstone)
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Related to Alumstone: potassium alum
A gray mineral, chiefly KAl3(SO4)2(OH)6, used in making alum and fertilizer.
[French, from alun, alum, from Latin alūmen.]
(Minerals) a white, grey, or reddish mineral consisting of hydrated aluminium sulphate. It occurs in volcanic igneous rocks and is a source of potassium and aluminium compounds. Formula: KAl3(SO4)2(OH)6
[C19: from French alun alum (from Latin alūmen) + -ite1]
a mineral, a hydrous sulfate of potassium and aluminum, KAl3(SO4)2(OH)6, commonly occurring in fine-grained masses. Also called al•um•stone (ˈæl əmˌstoʊn)